Methods and systems are provided for variable valve actuation assembly. In one example, the variable valve actuation assembly may include a first pressure reservoir with a first pressure fluidly coupled to valve actuators and positioned below an engine valve. A second pressure reservoir with a second pressure is arranged directly below the first pressure reservoir and a hydraulic medium flows between the first and second pressure reservoirs.

Systems and methods are provided for determining and correcting air/fuel imbalance between cylinders of an internal combustion engine. A deactivation strategy is determined and implemented. An evaluation is made of whether the engine is operating with an air/fuel imbalance between cylinders. When an imbalance is identified, an alternate deactivation strategy is implemented. Based on outcomes of the alternate deactivation strategy, a source cylinder of the air/fuel imbalance is identified, and fuel flow to the source cylinder is corrected.

A control device and a control method for a variable valve timing mechanism are provided so as to improve the accuracy of cam phase angle interpolation without using a motor rotation angle sensor. The control device for the variable valve timing mechanism includes a controller configured to detect a phase angle of a cam based on a cam signal and control the phase angle of the cam by using an electric motor. The controller is configured such that a motor torque estimation unit calculates a motor torque from a motor current based on motor characteristics, a motor rotation-angle estimation unit calculates a motor rotation angle at least based on the motor torque and an engine operating state, and a conversion unit and a feedback control unit interpolate the cam phase angle of the variable valve timing mechanism from the motor rotation angle.

A camshaft phaser assembly, including: an axis of rotation; a hydraulic camshaft phaser including a stator arranged to receive rotational torque and including a plurality of radially inwardly extending protrusions, a rotor arranged to be non-rotatably connected to a first camshaft and including a plurality of radially outwardly extending protrusions circumferentially interleaved with the plurality of radially inwardly extending protrusions, and a plurality of chambers bounded at least in part by the plurality of radially inwardly extending protrusions and the plurality of radially outwardly extending protrusions; an electric camshaft phaser including an output gear arranged to be non-rotatably connected to a second camshaft located concentrically within the first camshaft and an input non-rotatably connected to the stator; and a connection plate non-rotatably connecting the input and the stator. The rotor and the output gear are rotatable with respect to each other about the axis of rotation.

A sensor for a motor vehicle, the vehicle including a combustion engine and an engine control computer. The engine includes at least one drive shaft able to be driven in rotation, the at least one drive shaft having at least one magnetic element, the sensor being disposed facing the at least one magnetic element, the computer being configured to determine the angular position of the at least one drive shaft in relation to a predefined reference angular position on the basis of an output signal supplied by the sensor, the sensor being characterized in that it is able to generate a square wave output signal. Each square wave is characterized by an initial instant and a temporal width, by associating each initial instant with a predefined angular position of the drive shaft.

An internal combustion engine comprises a crankshaft, at least one camshaft adjustable electromechanically by an actuating gearing, an engine control unit, and a camshaft control unit for controlling an actuating motor which operates the actuating gearing. The engine control unit is linked to a device for detecting the angular position of the crankshaft, and the camshaft control unit is linked to the engine control unit. A device for detecting a reference position of the camshaft and a device for detecting the angular position of the shaft of the actuating motor are provided as sole mechanisms for detecting the angular position of the camshaft. The camshaft control unit is designed to determine the phase angle of the camshaft in relation to the crankshaft on the basis of the information items provided by said devices in combination with the detected angular position of the crankshaft and the transmission ratio of the actuating gearing.

The valve timing control unit includes a valve timing control mechanism that includes a driving rotary body, a driven rotary body, an electric motor and a deceleration gear each for setting the relative rotational phase of the driving rotary body and the driven rotary body, and a phase sensor unit that detects the actual phase of the driving rotary body and the driven rotary body. The valve timing control unit includes a controller that controls the electric motor to reduce a phase difference between the actual phase and a target phase, and the controller includes a swing controller that swings the target phase in vicinity of the target phase when the target phase is maintained and the actual phase having a fluctuation amount is held in a holding region, in which the fluctuation amount is less than a preset value.

A valve mechanism includes a valve, a camshaft, an intermediate swing arm located between a cam and the valve, a lift regulating mechanism and a roller assembly. The cam drives the valve to move by means of the intermediate swing arm. The roller assembly is supported by the cam, an eccentric wheel of the lift regulating mechanism and an intermediate swing arm roller. A peripheral surface of the eccentric wheel includes a lift regulating section having a start point and an end point, a maximum lift point of the lift regulating section is located between the start point and the end point, and the lift regulating section is divided into a first section which is convex and a second section having at least a part thereof concave.

An internal combustion engine comprises a crankshaft, at least one camshaft adjustable electromechanically by an actuating gearing, an engine control unit, and a camshaft control unit for controlling an actuating motor which operates the actuating gearing. The engine control unit is linked to a device for detecting the angular position of the crankshaft, and the camshaft control unit is linked to the engine control unit. A device for detecting a reference position of the camshaft and a device for detecting the angular position of the shaft of the actuating motor are provided as sole mechanisms for detecting the angular position of the camshaft. The camshaft control unit is designed to determine the phase angle of the camshaft in relation to the crankshaft on the basis of the information items provided by said devices in combination with the detected angular position of the crankshaft and the transmission ratio of the actuating gearing.

An electromechanical camshaft phaser (3) comprises a setting gear (4) and an electric motor (5), which is controlled by means of an electric-motor control unit (6). Data concerning the operation of the electric motor (5) including position changes of its motor shaft are transferred via a data bus (8) from the electric-motor control unit (6) to an engine control unit (7) of the internal combustion engine (1) comprising the camshaft phaser (3). In addition, recurring time signals are transferred from the electric-motor control unit (6) to the engine control unit (7) via a separate line (9), by which harder real-time requirements are met than by the data bus (8). The time signals are used to generate a time difference signal in the engine control unit (7) by comparison with the data received by the engine control unit (7), which time difference signal is fed back to the electric-motor control unit (6) via the data bus (8) and is used there to synchronize the electric-motor control unit (6) with the engine control unit (7).