The electromechanical camshaft phasing unit developed and produced by Schaeffler, is about to be used for the first time in volume production in a series of Japanese engines.
The use of electromechanical phasing units, instead of the current standard hydraulic systems, allow the camshaft to adjust more quickly and accurately to the prevailing engine conditions. This reduces consumption and harmful emissions, while simultaneously increasing comfort during stop/start operation.
Electromechanics make it possible to phase the camshaft at speeds up to 600 crank angle degrees per second. Hydraulic systems operate from two to ten times more slowly, irrespective of the engine speed and temperature. The increased dynamics allow very fast reactions to changes in load. Unlike hydraulic systems, the reaction speed to a change in load is not dependent on the oil supply, so a larger engine oil pump is not required.
Also, starting and stopping the engine is much smoother with electromechanical camshaft phasing units. This is important not only in stop/start operation but above all for hybrid vehicles. It is possible to start the internal combustion engine without any noticeable judder because, up to 200 rpm, the engine runs with reduced compression.
The system consists of a brushless DC motor and a gear unit with a high reduction ratio. The motor also acts as a sensor, so the precise position of the camshaft is always known.