Zf Friedrichshafen Ag

2F Friedrichshafen Ag

Konrad Thoma

Stefan Unseld

Frank Richter

Jürgen Pescheck

Ilja Imgrunt

A clutch or brake with an electrically actuated switching coil and an armature that axially moves toward the switching coil and forms a connection with the switching coil and can rotate relative to the switching coil, in an adjustment system for camshafts of a combustion engine. A superposition transmission has an input driven by a crankshaft of the engine, a drive output element that drives a camshaft of the engine and a control element, by which relative rotation between the input and the output can be produced by applying a braking torque. The armature is rotationally fixed and axially slidable, and centered on or at a transmission component, and the switching coil is rotationally fixed and centered coaxially with the armature by a membrane spring on a further transmission component, relative to which the armature is braked or to which the armature is coupled.

Clutch or brake in or at a gearbox

The invention concerns an adjustable hysteresis driver, with a rotor component () on the input side that can be driven and/or a stator component (), with an armature component () on the output side in fixed connection with a shaft (), with a hysteresis component () connected to the armature component (), the stator component () comprising an electromagnet () or permanent magnet () by means of which a magnetic flux can be induced in the rotor component () and/or the stator component (&#x2033;), and in which the torque that can be transmitted can be adjusted by electromagnetic or electro-mechanical means. The purpose of the invention is to propose a hysteresis driver with improved adjustability. To achieve this it is provided that the hysteresis driver consists of a hysteresis clutch or a hysteresis brake and has active operating means for implementing a 'fail-safe' function, which, if the current supply to the electromagnet () fails, ensures that a torque is transferred either by a mechanical coupling or by the action of permanent magnet force between the rotor component () of a hysteresis clutch or the stator component (&#x2033;) of a hysteresis brake and the said armature component ().

Adjustable hysteresis driver

An electromagnetically operated unit for controlling a radial connection. The unit has a first device which is optionally coupleable with a second device. The second device includes a magnet and/or electromagnet. The unit also has radially movable switching elements that are supported about the circumference of one of the devices, which additionally has contoured and/or frictional surfaces, which mate with respective contoured and/or frictional surfaces of the other one of the devices, thus effectuate engagement of the first and second devices. When the unit is designed with a closed current system the switching elements are biased to disengage when current is applied to the magnet and with an open current system the switching elements are biased to engage, against the force of a spring, when current is applied to the magnet.

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Friedrichshafen, Germany

Konrad Thoma