A valve drive for an internal combustion engine, including a gas exchange valve; a first mechanically driven drive mechanism; and a second drive mechanism connected to the gas exchange valve to move same. The first and second drive mechanisms connected via a hydraulic coupling device that has a pressure chamber, which can be relieved of pressure via a valve device and is designed to couple the drive mechanisms by hydraulic pressure and to decouple same in a pressure-relieved state. The valve device has two switch valves fluidically connected to the pressure chamber in parallel and via which the pressure chamber is relieved of pressure in the open state of at least one of the switch valves. The valve drive has a controller that actuates the switch valves in a delayed manner to provide a variable valve stroke of the gas exchange valve during a stroke movement.

A camshaft phaser arrangement configured for a concentric camshaft assembly having inner and outer camshafts is provided. The camshaft phaser arrangement includes a first camshaft phaser, a second camshaft phaser, a coupling, and at least one timing wheel connected to at least one of the first or second camshaft phaser. Each of the camshaft phasers is configured to be connected to either the inner or the outer camshaft. The at least one timing wheel defines at least one cutout that is configured to receive at least a portion of the coupling.

A camshaft phaser arrangement configured for a concentric camshaft assembly having inner and outer camshafts is provided. The camshaft phaser arrangement includes a first camshaft phaser, a second camshaft phaser, a coupling, and at least one timing wheel connected to at least one of the first or second camshaft phaser. Each of the camshaft phasers is configured to be connected to either the inner or the outer camshaft. The coupling includes a coupling ring and at least one coupling pin that torsionally connects the first camshaft phaser to the second camshaft phaser. The coupling provides for radial and axial movement between the first camshaft phaser and the second camshaft phaser.

Methods and systems are provided for diagnosing a cylinder valve deactivation mechanism in an engine system having cam-actuated valves. Movement of a latch pin of the deactivation mechanism is inferred from an induction current generated by a solenoid coupled to the latch pin, and the inferred movement is used to diagnose operation of cylinder valve deactivation mechanism. The inferred movement and a profile of the induction current is also used to estimate camshaft and crankshaft timing for improved cylinder fuel delivery in the absence of a camshaft sensor.

A variable valve timing control device includes a phase detecting portion; a phase control portion driving an electromagnetic solenoid while obtaining a detection signal detected by the phase detecting portion to set a spool to one of a phase control region and a lock region; and a boundary memory portion memorizing a boundary electric current value for referring a boundary between the phase control region and the lock region when the phase control portion operates a phase control; and a characteristic calculation portion obtaining the boundary electric current value by calculation, the boundary electric current value supporting the boundary between the phase control region and the lock region based on solenoid characteristic information of the electromagnetic solenoid and valve characteristic information of an electromagnetic control valve, the characteristic calculation portion memorizing the boundary electric current value to the boundary memory portion.

An internal combustion engine includes a cylinder head and a valvetrain including a poppet valve, a cam shaft on which is mounted a cam, and a rocker arm assembly. The rocker arm assembly includes a rocker arm and a cam follower configured to engage the cam as the cam shaft rotates. The rocker arm assembly is operative to transmit force from the cam to actuate the valve and includes an electrical device mounted to the rocker arm. A first electrical circuit includes the electrical device and a first conductor mounted to the rocker arm and a second electrical circuit includes a second conductor mounted off the rocker arm. The first and second conductors are inductively coupled to an extent that enables effective power transfer or communication between them. Inductive power transfer avoids the use of wires that could become caught, clipped, or fatigued and consequently short out.

A multiple variable valve lift apparatus disposed at an intake part and an exhaust part of an engine includes: a moving cam rotating together with a camshaft, being movably disposed in an axial direction of the camshaft, and forming a plurality of cams for realizing valve lift to be different from each other and a cam guide protrusion; an operating unit selectively guiding the cam guide protrusion so as to move the moving cam in an axial direction of the camshaft; a controller controlling an operation of the operating unit; and a valve opening/closing unit opened/closed by contacting any one among the plurality of cams.

A valvetrain for an internal combustion engine of the type that has a combustion chamber, a moveable valve having a seat formed in the combustion chamber, and a camshaft includes a rocker arm assembly, a pivot providing a fulcrum for a rocker arm of the rocker arm assembly, and a latch assembly. An electrical device mounted to the rocker arm assembly receives power or communicates through a circuit that includes an electrical connection formed by abutment between surfaces of two distinct parts. The rocker arm assembly is operative to move one of the two abutting surfaces relative to the other in response to actuation of the cam follower. Forming an electrical connection through abutting surfaces that are free to undergo relative motion may reduce or eliminate the need to run wires to a mobile portion of the rocker arm assembly.

A method for controlling a valve arrangement for an internal combustion engine, the valve arrangement including a piston arrangement comprising a piston having a piston end portion facing an inlet valve of the valve arrangement. The method includes receiving a signal indicative of a temperature level of an exhaust gas after treatment system and when the signal indicates a temperature level below a predetermined threshold level: advancing an exhaust event of the internal combustion engine; and controlling the piston arrangement for reducing the distance between the piston end portion and the inlet valve before the internal combustion engine assumes an air intake event.

Methods and systems are provided for diagnosing a cylinder valve deactivation mechanism in an engine system having cam-actuated valves. Movement of a latch pin of the deactivation mechanism is inferred from an induction current generated by a solenoid coupled to the latch pin, and the inferred movement is used to diagnose operation of cylinder valve deactivation mechanism. The inferred movement and a profile of the induction current is also used to estimate camshaft and crankshaft timing for improved cylinder fuel delivery in the absence of a camshaft sensor.