Patent ID: 9494058
Filing Date: 2016-11-15
CPC Classification: F01L

Claim Text:
1. A variable cam phaser for an automobile engine for varying a phase angle of a camshaft of an apparatus relative to the crankshaft of the engine to vary an open/close valve timing of the engine in accord with rotational movements of two control rotors about a camshaft axis by means of a torque of the crankshaft and opposite torques of two electromagnetic actuators, the apparatus comprising: a cam angle sensor for detecting a current angle of the camshaft; a crankshaft angle sensor for detecting the current angle of the crankshaft; a deviation calculator for calculating a deviation or difference between a current phase angle of the camshaft relative to the crankshaft detected by the cam angle sensor and a target phase angle of the camshaft relative to the crankshaft and relative to the crankshaft; a sign determinator that determines the plus/minus sign of the deviation; a threshold discriminator that determines whether or not the deviation is within a predetermined threshold range; an operation command section for commanding the two electromagnetic actuators to hold the two control rotors unrotatable relative to each other when the deviation is within the threshold range, but otherwise commanding one of the two electromagnetic actuators selected in accord with a sign of the deviation determined by said sign determinator to decrease its torque; and a driver circuit for actuating one or two of the electromagnetic actuators in response to a operation command from the operation command section.