Patent ID: 7201124

Claim:
Phase displacement device for displacing a phase between a camshaft ( 9 ) and a crankshaft ( 12 ), the phase displacement device ( 1 ) comprising a transmission ( 5 ), an electric motor ( 2 ) having a rotor ( 3 ) and a drive shaft ( 4 ) driven by the rotor ( 3 ), a first sensor device ( 14 , 18 , 19 ) for measuring a rotational speed or a position of at least one of the drive shaft ( 4 ) and the rotor ( 3 ) of the electric motor ( 2 ), and a second sensor device ( 13 ) for measuring a rotational speed of the crankshaft ( 12 ) at least during phase displacement, whereby a first actual angle of the phase of the camshaft ( 9 ) relative to the crankshaft ( 12 ) is determined by values generated by the first sensor device ( 14 , 18 , 19 ) and the second sensor device ( 13 ), and a third sensor device ( 11 ) measures a rotational speed of the camshaft ( 9 ), wherein a second actual angle of the phase of the camshaft ( 9 ) relative to the crankshaft ( 12 ) is determined when the rotational speed of the crankshaft ( 12 ) is sufficiently high by the values generated by the second and third sensor devices ( 13 , 11 ), whereby the first actual angle is aligned with the second actual angle if a second actual angle is determined.