Andreas Stihl Ag Co. Kg

Mahle International Gmbh

Andreas Neubauer

Tim Gegg

Gernot Liebhard

Claus Naegele

Alfred Elsässer

Wolfgang Layher

Heinrich Leufen

Eberhard Schieber

Ernst Gorenflo

Michael Krappel

Thomas Riemay

Manuel Dangelmaier

Rene Wichert

Simon Trinkle

Oliver Fritz

Martin Helmis

René Wichert

Jörg Präger

Michael Harrer

Robert Böker

Stephan Weber

Claudius Kischka

Thomas Keller

An external rotor of a device for contactless transmission of rotary movements, for example of an electric motor, a magnetic transmission, a generator or a magnetic coupling, may include a plurality of different permanent magnet segments configured ring segment-like that are alternatingly arranged in a closed permanent magnet segment ring. At least one lateral surface of at least one permanent magnet segment of the plurality of permanent magnet segments may deviate from a radial direction. The at least one permanent magnet segment via the at least one lateral surface may be in contact with another permanent magnet segment of the plurality of permanent magnet segments.

External rotor of a device for the contactless transmission of rotary movements

The invention is directed to a method for braking an electric drive motor having a stator and a rotor. The stator has field coils which have electrical phase connections for three motor phases. To generate an electromagnetic rotating field driving the rotor, the phase connections are connected to a supply voltage via switches actuated by a control unit which closes the switches depending on the rotary position of the rotor. To brake a rotating rotor, a braking current is generated by short-circuiting the phase connections. A phase short circuit is switched in between each two phase connections of the field coils with a preset temporal sequence to brake the rotor. The phase connections short-circuited are each selected corresponding to the rotary position of the rotor so that that field coil is short circuited in which the voltage induced by the magnetic field of the rotating rotor passes through its maximum.

Method for braking an electric drive motor

A portable, handheld work apparatus such as a chain saw has a handle () to guide the work apparatus () and has an air-cooled, mixture-lubricated combustion engine () arranged in a casing as a drive for a work tool (). The cylinder () has a combustion chamber () formed therein to which an air/fuel mixture is supplied. The air/fuel mixture is ignited by a spark plug () which projects into the combustion chamber (). An ignition control () triggers a spark in dependence on the angular position of the crankshaft (). A temperature sensor () is provided to control the cylinder temperature. The temperature signal of the temperature sensor () is connected to a power control (). When a predetermined temperature is exceeded, the power control () changes the operating parameters of the combustion engine () in such a manner that the power of the combustion engine () is changed.

Handheld work apparatus having an air-cooled combustion engine

The invention relates to a portable, handheld work apparatus such as a trimmer, a cut-off machine, a chain saw or the like, having a motor () to drive a rotating, exchangeable work tool (). A control unit () serves to control the operation of the motor (). The control unit () determines the rotational speed (n) and/or the power (P) of the motor (). According to the invention, the motor () can be operated in a first operating mode (I) with reduced rotational speed (n) and/or power (P) and in at least a second operating mode (II) with an increased rotational speed (n) and/or power (P). In dependence on a release signal, the control uses exclusively the first operating mode (I) for a limited operation and the second operating mode (II) for an expanded operation.

Handheld work apparatus with switchable power

In a method for operating an internal combustion engine for adjusting a desired fuel/air mixture, wherein the rotary speed is determined by an operating curve based on a fuel/air mixture composition, wherein the operating curve has ascending and descending branches and a maximum, wherein a lambda value is smaller than 1 on the descending branch, it is first determined by statistic evaluation whether the operating point is on the ascending or descending branch. In a second method step, when the operating point is not on a desired branch of the operating curve desired as a starting point for a third method step, at least one operating parameter is changed until the operating point is positioned on the desired branch. In a third method step, the maximum of the operating curve is determined. Based on the determined maximum, the desired operating point of the internal combustion engine is then adjusted.

Method for operating an internal combustion engine

The invention relates to a portable handheld work apparatus such as a cutoff machine, motor-driven chain saw, brushcutter, blower apparatus or the like. The apparatus includes a drive motor () for driving a work tool () and is provided with a security circuit (). The security circuit () switches the drive motor () of the work apparatus into an operational-ready state or into an out-of-service state in dependence upon received signals of a receiver unit (). The receiver unit is configured to receive at least one operating code. The receiver unit () is configured for receiving a service code () and, with the receipt of a service code, switches the drive motor into only a temporary service state.

Use block for a handheld work apparatus

An internal combustion engine () has an ignition device, a device for supplying fuel and a device for detecting the rpm of the engine (). The engine () includes a permissible limit rpm (n) and a control range (A) of the rpm (n) above the limit rpm (n). A method for operating the engine () provides that the rpm of the engine () is limited in the control range (A) because of suppression of the ignition in individual engine cycles wherein the rpm (n) lies above a control rpm (n) lying in the control range (A). In the control range, and to improve the exhaust-gas values, the noncombustion engine cycle ratio (NECR) is adjusted. The NECR indicates the ratio of the number of engine cycles wherein the ignition is suppressed to the total number of ignitions.

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Ludwigsburg, Germany

Andreas Neubauer