Zf Friedrichshafen Ag

Zf Batavia L.l.c.

Hans-Joachim Martin

Anton Fritzer

Thilo Schmidt

Gerhard Gumpoltsberger

Josef Haupt

Wolfgang Rieger

Markus Herrmann

Rainer Novak

Michael Ebenhoch

Tobias Pfleger

Michael Drabek

Stefan Csajagi

Rudolf Kauffeldt

Jens Schmidt

J&uuml;rgen Mittelberger

Florian Langenbacher

Marco Berner

Werner Zeller

Hans-Juergen Bader

Tobias Schmidt

A hydraulic control unit () for a transmission () of a motor vehicle drive train may include a housing top section (), a first valve housing () having a first valve (), and a second valve housing () having a second valve (). The first valve () is aligned along a first direction () and the second valve () is aligned along a second direction (), wherein the first direction () differs from the second direction ().

Hydraulic control unit for a transmission

A pressure back-up valve () includes a release piston () movable between first and second stop positions and a closing body () movable to a closing position in which this separates first and second connection pressure chambers () when the release piston () is in a first stop position. The release piston () moves the closing body (), in the second stop position, into an opening position. The release piston () is pressurizable on a first pressure surface (A) from a first side via a third connection pressure chamber () and on a second pressure surface (A) from a second side via a second connection pressure chamber (). The closing body () is pressurized, in the closing position, from a first side via the second connection pressure chamber () on a first pressure surface (A) and from a second side via the first connection pressure chamber () on a second pressure surface (A) of the closing body ().

Pressure back-up valve

A hydraulic control unit for a transmission includes a lower side housing, an upper side housing and an intermediate plate. The lower side housing and the upper side housing form a hydraulic supply channel section, which is connected in the intermediate plate by an aperture. At the inlet of the aperture, at least one recess with a predetermined depth is provided for bounding an inlet cross-section.

Hydraulic control system

A valve system for controlling a system pressure control system, in particular a hydraulic control unit of an automatic transmission, includes a multi-stage system pressure valve, a pilot valve and a control valve with a control piston downstream from the pilot valve that governs the pressure at a differential area of the system pressure valve, depending on the pilot pressure. The pilot pressure/system pressure characteristic curve features a continuous development, and whereas, from a predefined pilot pressure, on the basis of a sudden change to the dependency of the change to the system pressure as a function of the change to the pilot pressure, the gradient of the system pressure as a function of the pilot pressure is significantly steeper than that prior to the predefined pilot pressure.

Valve system for controlling a system pressure control system

A hydraulic shifting device for an automatic transmission for engaging and disengaging a parking lock. The shifting device comprises a parking lock cylinder () for actuating the parking lock, and a parking lock valve () which, for hydraulic control of the parking lock cylinder (), can be switched to at least first and second shift positions. In this case the hydraulic shifting device comprises a further parking lock valve (), and the two parking lock valves () and the parking lock cylinder () are designed and connected with one another in such manner that the parking lock can only be disengaged by pressurizing the parking lock cylinder () if the two parking lock valves () are each switched to a particular shift position.

Hydraulical shifting device for an automatic transmission

A pressure medium supply device of a hydraulically actuated shifting element (K, K) comprises at least one pressure medium supply duct () in communication with a pump () and a line () for pre-filling of the shifting element. An additional pressure-retaining valve () or a check diaphragm is integrated in the pressure medium supply duct (), between the shifting element and the shifting element valve (), and can be closed in the draining direction of the pressure medium supply duct (). The pressure-retaining valve () is designed such that the shifting element can be drained and the pressure medium supply device can be vented.

Pressure medium supply device of a hydraulically actuated shifting element

A bypass valve for a cooler connected downstream from a hydraulic aggregate. The bypass valve includes a housing with ports for connection to the hydraulic aggregate and the cooler. A closure element is located in the housing for closing and opening a bypass. A spring pushes the closure element into a closing position, and thermo-sensitive means causes the closure element to open if the temperature of the hydraulic fluid is below a threshold temperature. The thermo-sensitive means are formed by the valve spring, which is made of a memory-metal alloy with a transition point close to the threshold temperature such that below the threshold temperature it no longer exerts a force and allows the closure element to open.

Bypass valve for a cooler connected downstream of a hydraulic unit

A shifting device () for shifting a motor vehicle transmission with a shift selector shaft on which a plurality of shift elements () such as shift forks or shift rockers () are arranged and can be displaced to carry out a shifting operation. The shifting device () includes one hydraulic shift cylinder (), that can be actuated from both sides, with a piston () that can be displaced within a cylinder housing () and which is actively connected with a shift element () to be actuated. To simplify a shifting device () of this type, the piston () has a piston rod () that follows the movement of the piston () and can be connected directly to the shift element () in a detachable manner.

Shifting device for shifting a motor vehicle gear box

A bypass valve for blocking oil flow through a radiator from a transmission with low oil temperatures includes an oil supply from the radiator, an oil supply, via a bypass line, an oil outlet and a valve unit arranged inside the valve housing. The valve unit includes a compression spring and a heat sensitive element, which move depending on the oil temperature such that when the temperature falls below a threshold value, the oil supply from the radiator is closed and the supply, via a bypass line, is opened. When the oil temperature rises above the threshold value, the oil supply from the radiator is opened and the supply, via the bypass line, is closed. The valve unit can be axially moved against the force of the compression spring, when a predefined oil pressure is reached, thus opening the supply, via the bypass line.

Device for uncoupling the oil flow through a radiator

The device for the contactless measurement of the rotational speed of a first part which rotates during operation and which is arranged inside a second part that either does not rotate or rotates at a rotational speed that is independent of the rotational speed of the first part, has an arrangement which generates a magnetic field and a magnetic field detector, wherein the arrangement which generates the magnetic field has a magnet ring ( ) integrated in the inner part ( ) and wherein the magnetic field detector is a Hall-effect sensor ( ) situated in a housing ( ) that surrounds both parts: the second part ( ) consists of a non-magnetizable material.

Growing community of inventors

Kressbronn, Germany

Hans-Joachim Martin