Zf Friedrichshafen Ag

Tobias Pfleger

Rainer Novak

Anton Fritzer

Markus Terwart

Alexander Hoffmann

Markus Moosmann

Andreas Feiner

Andreas Roedler

Karsten Kudermann

Hans-Joachim Martin

Georg Ege

Florian Langenbacher

Adolf Bucher

Jens Schmidt

Hans-Ulrich Nonnast

Marco Berner

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 valve (V, V, V) includes a housing (VG) and a piston (VK) displaceably guided therein. A first end (VK) of the piston (VK) can be acted upon by a force, with the aid of which the piston (VK) is displaceable against a spring (F) acting upon a second end (VK) of the piston (VK). The valve (V, V, V) has four switching conditions, in which four ports (A, B, P, T) in the housing (VG) are selectively connectable to one another or blocked with respect to one another. In a first switching condition, none of the ports (A, B, P, T) are connected to one another. The spring (F) is configured in such that, in the absence of an application of force onto the first end (VK), the piston (VK) is held in a position, which corresponds to the first switching condition of the valve (V, V, V).

Valve, hydraulic system and motor vehicle gearbox

A hydraulic system (HY) for a motor vehicle transmission (G) includes at least one pump (P), two pump output lines (P, P) for supplying a first pressure circuit () and a second pressure circuit (), and an electromagnetically actuated, first pressure control valve (EDS), the inlet (EDS) of which is connected to the first pressure circuit () and the outlet (EDS) of which is connected to a first control surface (PVC) of a spring-loaded shut-off valve (PV). The shut-off valve (PV) is configured for connecting, in a non-actuated condition, the second pump output line (P) to the second pressure circuit () and, in the condition actuated via the first control surface (PVC), disconnecting the second pump output line (P) from the second pressure circuit (). A motor vehicle transmission (G) including such a hydraulic system (HY) and a drive train including such a motor vehicle transmission (G) are also provided.

Hydraulic system for a motor vehicle transmission

A method for operating a parking lock device () with a hydraulic system (), the method including, when there is a demand to engage the parking lock device () originating from a disengaged operating condition of the parking lock device (), applying a pilot pressure (p_EDS) at the parking lock valve (PSV) and applying the main pressure (p_sys) at the parking lock valve (PSV), if necessary, via the positioning valve (POSV). The pilot pressure (p_EDS) and the main pressure (p_sys) are each guided to defined pressure levels at which the parking lock valve (PSV) is transferrable into the further operating condition range of the parking lock valve (PSV) by the active actuating force against the pilot pressure (p_EDS) and against the pressure between the parking lock valve (PSV) and the parking lock cylinder ().

Method for operating a parking lock device by means of a hydraulic system

A pressure control valve () includes a pressure port (P), a consumer port (A), a tank port (T), and a piston (K) which is displaceable counter to the force of a first spring (F) and a second spring (F). The springs (F, F) and area ratios of the pressure control valve () are designed such that the pressure port (P), in the non-pressurized condition, is connected to the consumer port (A) via an opening cross-section of the pressure control valve (). An opening cross-section between the pressure port (P) and the consumer port (A) decreases depending on the pressure at the consumer port (A), and, upon attainment of a limiting pressure at the consumer port (A), the consumer port (A) is connected to the tank port (T). A related hydraulic system (HY) and a related motor vehicle transmission (G) are also provided.

Pressure control valve

A hydraulic system of a transmission includes a plurality of pressure control valves. A pilot force component and an actuating force component of additional pressure control valves are applicable in the direction of a first end position of a valve slide. A downstream pressure of the additional pressure control valves is applicable in the direction of a second end position of the valve slide. Clutch valves are configured to be brought into operative connection by a pilot-controlled valve unit with an area guiding pressure of a primary pressure circuit or with an additional valve unit. The additional valve unit is a pressure-limiting valve with a predefined pressure level adjusted upstream of the additional valve unit and connected downstream to a low-pressure area.

Hydraulic system of a transmission with a multiple number of pressure control valves

A method for operating a parking lock device with a hydraulic system, the method including applying the pressure between the parking lock valve and the pressure chamber at the parking lock valve against the actuating force. Moreover, when there is a demand to disengage the parking lock device, the method includes applying the pilot pressure at the parking lock valve against the actuating force when the pressure between the parking lock valve and the pressure chamber of the parking lock valve is less than a threshold value at which the parking lock valve is transferred into a further operating condition range. Additionally, when there is a demand to disengage the parking lock device, the method includes adjusting the pilot pressure applied at the positioning valve to a pressure level at which the positioning valve is transferred into or held in its defined operating condition range.

A multi-speed transmission with hydraulically actuated shift rods, wherein an actuating pressure (p_B) is applicable by a valve device () and shuttle valves (C toD) to piston chambers (A toB) of pistons (to), the actuating pressure being adjustable by valves (). The piston chambers (A toB) can be brought into operative connection with a low-pressure region () by the shuttle valves (C toD) and a prefilling valve () or by the shuttle valves (C toD), the valve device (), and the valves (). Each of the shuttle valves (C toD) has a spring assembly (E toF), by which the shuttle valves (C toD) are held below a pressure threshold of the actuating pressure (p_B) in an operating state that connects the piston chambers (A toB) to the low-pressure region () by the prefilling valve ().

Multi speed transmission device with hydraulically actuated shift rods

A transmission includes a hydraulic system connected to a hydraulic pump and to an additional hydraulic pump. A secondary pressure circuit is connectable to a primary pressure circuit with a system pressure valve. A pressure side of the hydraulic pump is coupled directly with the primary pressure circuit and connectable to the secondary pressure circuit with the system pressure valve. A pressure side of the additional hydraulic pump is coupled directly with the secondary pressure circuit. The pressure side of the hydraulic pump proximate the secondary pressure circuit is connectable to a gear set, to a dual-clutch system and to a suction area of the hydraulic pump and the additional hydraulic pump by a valve device. The pressure side of the additional hydraulic pump is in connection with the gear set and is connectable with the dual-clutch system by the valve device.

Transmission device having a hydraulic system

A device for ensuring the supply of oil to the secondary circuit of a transmission of a hybrid drive-train of a motor vehicle, having an electrically operated auxiliary oil pump, which comprises a bypass valve that is connected between the outlet of the auxiliary oil pump and the secondary circuit of the hybrid circuit of the transmission, such that the valve opens at a predetermined opening pressure, closes at a predetermined closing pressure which is lower than the minimum system pressure, and, at a predetermined pressure between the opening and closing pressures, the valve permits flow a predetermined volume flow into the secondary circuit.

Device for providing the oil supply of a secondary circuit of a transmission of a hybrid driveline of a motor vehicle, comprising an auxiliary electrically driven oil pump

A temperature sensor arrangement in an automatic transmission in which the temperature sensor () is arranged such that oil leaked from the hydraulic system permanently flows around it.

Temperature sensor arrangement in an automatic gearbox

A bleed valve () for a pipe into which a non-return function is integrated. The bleed valve is preferably designed to be a thermal valve.

Bleed valve

A device for the hydraulic control of an automatic transmission, especially a continuously variable automatic transmission. The control system comprises a forward/reverse drive unit (), which is controlled by way of at least a first and a second shifting component (). The shifting components () are in turn controlled via at least two valves (), which are pressurized by way of a pressurized medium pump (). A gear selector device () selection is made among at least a forward gear (D), a neutral gear (N) and a reverse gear (R), wherein the selector device () possesses a non-mechanical connection to the transmission control system.

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Markdorf, Germany

Tobias Pfleger