An oil supply system of an automatic transmission or an automated manual transmission in a power train has an oil pan and a pressure line for supplying elements of the transmission with pressurized oil. A pumping device pumps oil from the oil pan into the pressure line at a supply pressure P.sub.0. A hydrodynamic converter, being a starting element, forms a subsection of the pressure line. A hydrodynamic retarder is disposed in a retarder oil circuit. At least a first switching valve, a second switching valve and a heat exchanger, wherein the heat exchanger is selectively switchable, by way of the switching valves, as a subsection into the pressure line or the retarder oil circuit. A temperature sensor is provided following the pumping device in the direction of flow in order to detect the oil temperature in the pressure line.

A method of producing a friction material. The method includes mixing silica containing filler particles and a liquid binder to form a binder-filler liquid mixture. The method also includes saturating a fibrous base material with the binder-filler liquid mixture to form a saturated fibrous base material. The method further includes curing the saturated fibrous base material at a predetermined temperature for a predetermined time to cure the saturated fibrous base material to form the friction material.

An electric drive device for a vehicle includes: a rotating machine that is used as a driving force source for traveling of the vehicle; a differential device configured to distribute power transmitted from the rotating machine to right and left driving wheels; and a retarder provided in a power transmission path between the rotating machine and the differential device and configured to generate a braking force. The retarder is either an electromagnetic retarder or a fluid retarder. The rotating machine and the retarder are arranged on opposite sides of an axis of the differential device in a front-rear direction of the vehicle in a plan view seen from above the vehicle, the axis of the differential device being parallel to a width direction of the vehicle.

An electric drive device for a vehicle includes: a rotating machine that is used as a driving force source for traveling of the vehicle; a differential device configured to distribute power transmitted from the rotating machine to right and left driving wheels; and a retarder provided in a power transmission path between the rotating machine and the differential device and configured to generate a braking force. The retarder is either an electromagnetic retarder or a fluid retarder. The rotating machine and the retarder are arranged on opposite sides of an axis of the differential device in a front-rear direction of the vehicle in a plan view seen from above the vehicle, the axis of the differential device being parallel to a width direction of the vehicle.

A method for learning braking step threshold values of a sustained-action brake includes detecting a braking requirement setpoint, controlling the sustained-action brake with the braking requirement setpoint to generate a braking effect variable of the sustained-action brake, and detecting a sustained-action brake actual braking effect variable and a maximum sustained-action brake braking effect. The method additionally includes forming a braking effect variable coefficient that characterizes a ratio of the sustained-action brake actual braking effect variable and the maximum sustained-action brake braking effect variable that results from control of the sustained-action brake with the braking requirement setpoint, and assigning the braking effect variable coefficient to a braking step of the sustained-action brake such that each braking step is assigned only one braking effect variable. Additionally, the method includes storing the braking requirement setpoint that results in the braking effect variable coefficient.

This invention seeks to replace traditional brakes with a safer and more economical design. The traditional design uses friction to slow a vehicle, while the proposed design uses hydraulic fluid to slow down the motion of a vehicle. The rotor blade, whose design is shown in FIG. 1B, is mounted upon the bearing and is housed with the hydraulic fluid in the housing in FIG. 1A.

A power transmission device has a reverse torque converter and a planetary gear mechanism with a ring gear, sun wheel and planet carrier with several planets. An input is connected to an impeller of the reverse torque converter and to a first element of the planetary gear mechanism. A turbine wheel is connected to a second element of the planetary gear mechanism, and a third element of the planetary gear mechanism is connected to or forms an output of the power transmission device. A selectable control clutch transmits power in a first rotation speed range, with an emptied reverse torque converter, between the input and the output of the power transmission device. A device supports and/or fixes the second element of the planetary gear mechanism, in particular the connection between the turbine wheel and the second element of the planetary gear mechanism in this first rotation speed range.

A hydrodynamic retarder system for a vehicle is provided. In a first operational state with the vehicle powered on and a retarder deactivated, a pump directs fluid flow from a fluid sump to a retarder inlet valve in the closed position and directs fluid flow to a second sump. In a second operational state with the vehicle on and the retarder activated, the retarder inlet valve moves to the open position directing fluid flow into a retarder chamber and flowing out of the retarder chamber after filling a second volume and discharging to the second sump.

A hydrodynamic retarder system for a vehicle is provided. In a first operational state with the vehicle powered on and a retarder deactivated, a pump directs fluid flow from a fluid sump to a retarder inlet valve in the closed position and directs fluid flow to a second sump. In a second operational state with the vehicle on and the retarder activated, the retarder inlet valve moves to the open position directing fluid flow into a retarder chamber and flowing out of the retarder chamber after filling a second volume and discharging to the second sump.

A hydrodynamic machine comprising: a toroidal working chamber including a first bladed wheel and a second bladed wheel arranged concentrically with the first bladed wheel; and an electrohydraulic system including an open loop unit and a and closed loop control unit, a working medium accumulator, a pump operable to pump a working medium from the working medium accumulator into the toroidal working chamber, a heat exchanger, a valve operable to switch between a first position, the first position being a non-braking position, and a second position, the second position being a braking position, and a line system operable to allow the pump to pump the working medium in both the first position and the second position into the working chamber.