A variable camshaft timing system including a first camshaft phaser having an input that is configured to receive rotational force from a crankshaft and an output that is configured to link with a first camshaft of a concentric camshaft assembly to change the angular position of the first camshaft relative to a crankshaft; and a second camshaft phaser having an output that is configured to link with a second camshaft of the concentric camshaft assembly to change the angular position of the second camshaft relative to the crankshaft, wherein the first camshaft is concentrically positioned to the first camshaft and the first camshaft phaser is mechanically linked to the second camshaft phaser to communicate rotational force from the crankshaft to the second camshaft phaser through the first camshaft phaser and the mechanical link.

The present disclosure relates to a cam phase adjuster that includes a stator, a rotor, a front cover and at least one locking pin. The cam phase adjuster is provided with a plurality of compartments formed between the rotor and the stator, and each compartment is divided into advance cavities and retard cavities in a circumferential direction; each locking pin is mounted in a corresponding mounting hole of the rotor; an end portion of each locking pin that faces away from the front cover abuts against the bottom of the corresponding mounting hole by means of a corresponding elastic reset member; an end face of the front cover that faces the rotor is provided with at least one locking groove which matches the at least one locking pin; the end portion of each locking pin that faces the front cover can be axially inserted into the corresponding locking groove; and the front cover is provided with an unlocking flow channel which fluidly connects the corresponding locking groove to one advance cavity or retard cavity.

The present disclosure provides systems and methods to compensate for backlash within a cam phasing system. For example, compensating for backlash by commanding a predetermined amount of additional actuator movement to account for backlash within a cam phaser. According to some aspects, a spring is provided within a cam phaser to unidirectionally take up the backlash within the cam phasing system.

A variable camshaft timing device that adjusts phase between a camshaft and a crankshaft includes a planetary gear assembly that changes an angular position of the camshaft relative to an angular position of the crankshaft; a sun gear configured to receive an output shaft of an electric motor that rotates at least a portion of the planetary gear assembly and controls phase adjustment between the camshaft and crankshaft by angularly displacing the camshaft with respect to the crankshaft; and a hydraulic lock (82) that releasably engages a portion of the variable camshaft timing device (10) in response to force applied by pressurized fluid thereby selectively preventing rotation of the camshaft relative to the crankshaft.

The present disclosure relates to a sliding cam system for an internal combustion engine. The sliding cam system has a camshaft and a plurality of cam carriers with in each case at least two cams, the plurality of cam carriers being arranged fixedly on the camshaft so as to rotate with it and in an axially displaceable manner. The sliding cam system has a plurality of fluid-actuated actuator apparatuses which are configured in each case for axially displacing a cam carrier of the plurality of cam carriers. The sliding cam system has a fluid feed apparatus which is provided for feeding a fluid in a fluidic connection upstream of the plurality of actuator apparatuses for actuating the plurality of actuator apparatuses. At least two actuator apparatuses of the plurality of actuator apparatuses are coupled fluidically for simultaneous actuation.

Systems and methods for managing excessive intake flow path pressure and counter flow are implemented to support enhanced engine braking applications, such as 2-stroke or 1.5-stroke engine braking implementations where the intake flow path may be exposed to excessive transient pressures in the combustion chamber during activation or deactivation of an engine brake. Intake throttle, exhaust gas recirculation (EGR) valve, intake manifold blow-off valve, compressor bypass valve, exhaust throttle, turbocharger geometry or turbocharger waste gate may be controlled to effectuate counter flow management separately or in combination. Excessive transient conditions may also be prevented or managed by sequential valve motion in which brake motion activation occurs first and then exhaust valve main event deactivation occurs second. Delay between brake activation and main event deactivation may be facilitated using mechanical and/or hydraulic implements as well as electronically.

Systems and methods for managing excessive intake flow path pressure and counter flow are implemented to support enhanced engine braking applications, such as 2-stroke or 1.5-stroke engine braking implementations where the intake flow path may be exposed to excessive transient pressures in the combustion chamber during activation or deactivation of an engine brake. Intake throttle, exhaust gas recirculation (EGR) valve, intake manifold blow-off valve, compressor bypass valve, exhaust throttle, turbocharger geometry or turbocharger waste gate may be controlled to effectuate counter flow management separately or in combination. Excessive transient conditions may also be prevented or managed by sequential valve motion in which brake motion activation occurs first and then exhaust valve main event deactivation occurs second. Delay between brake activation and main event deactivation may be facilitated using mechanical and/or hydraulic implements as well as electronically.

A switchable roller finger follower includes an inner lever, an outer lever pivotably mounted to the inner lever by a pivot axle, and a coupling device. The coupling device includes a coupling pin configured to move between a locked position in which the inner lever and the outer lever are connected together for movement in at least one direction and an unlocked position in which the inner lever is movable relative to the outer lever in the at least one direction. The coupling device also includes a spring configured to bias the coupling pin in the locked or unlocked position. A de-aeration flow path is formed between an oil passage and an opening for allowing air to move out of the oil passage, past the coupling pin, and exit through the opening. The de-aeration flow path switches between being open and closed based on a position of the coupling pin.

An internal combustion engine is provided with a variable valve operating apparatus, for use on a saddle-type vehicle. When a switching drive shaft is longitudinally moved under hydraulic pressure switched by a solenoid valve, a cam mechanism advances and retracts a switching pin. When the switching pin is advanced to engage in a lead groove in a cam carrier, the cam carrier is axially moved while rotating, to switch cam lobes to act on an engine valve. A solenoid valve is disposed on a left or right end in the leftward and rightward directions across the vehicle width, of a front or rear surface of a cylinder head. The solenoid valve is placed in an appropriate location in the cylinder head out of interference with other parts of the engine, thereby making the vehicle small in size.

A rocker arm comprises a hydraulic actuator piston slidably disposed in an actuator bore. An actuator spring is configured to bias the hydraulic actuator piston out of actuator bore and into contact with a valve train component or at least one engine valve, wherein reaction of the hydraulic actuator piston against the valve train component or the at least one engine valve biases a motion receiving portion of the rocker arm into contact with the valve actuation motion source. In an unactuated state of the hydraulic actuator piston, hydraulic fluid is permitted to flow out of the actuator bore and, in an actuated state of the hydraulic actuator piston, hydraulic fluid is locked in the actuator bore.