The systems and methods described herein provide an approach for cam phase angle control where an axial or rotational position of an actuator of a cam phaser has a direct relationship to the phase angle of the cam shaft, allowing for accurate cam phasing without the need for cam shaft or crank shaft position sensors. Providing phase angle adjustability without the need for crank shaft or cam shaft position sensors enables control of phase angle solely by sensing the axial or rotational position of the actuator of the cam phaser.

A camshaft may include a shaft as well as a sliding element that is disposed on the shaft such that the sliding element is axially displaceable along a shaft axis. The shaft may comprise an external tooth for transmitting torque between the shaft and the sliding element. The external tooth may engage a mating tooth geometry formed in a passage of the sliding element. The sliding element on its axial end faces may comprise bearing collars that with the shaft form radial supporting bearings of the sliding element on the shaft. Further, the shaft may comprise cylindrical bearing portions for forming the radial supporting bearings, wherein the bearing portions can be configured with a diameter that is smaller than a diameter circumscribed by tips of the mating tooth geometry that protrude into the passage of the sliding element.

A marine engine has an intake camshaft, an exhaust camshaft, and a crankshaft. Combustion in the marine engine causes rotation of the crankshaft which in turn causes rotation of the intake camshaft and exhaust camshaft. Rotation of the intake camshaft operates intake valves for controlling inflow of air to the marine engine. Rotation of the exhaust camshaft operates exhaust valves for controlling outflow of exhaust gas from the marine engine. A cam phaser is located at least partially inside at least one of the intake camshaft and the exhaust camshaft and is configured to vary a timing of operation of at least one of the intake valves and exhaust valves.

Cam phasing systems and methods are provided. In particular, a cam phasing system is provided that includes a reduced number of components when compared to current mechanical cam phasing systems. The cam phasing system includes a helix locking design that is configured to frictionally lock an helix rod during cam torque pulses.

Cam phasing systems and methods are provided. In particular, a cam phasing system is provided that includes a reduced number of components when compared to current mechanical cam phasing systems. The cam phasing system includes a helix locking design that is configured to frictionally lock an helix rod during cam torque pulses.

Cam phasing systems and methods are provided. In particular, a cam phasing system is provided that includes a reduced number of components when compared to current mechanical cam phasing systems. The cam phasing system includes a helix locking design that is configured to frictionally lock a helix rod during cam torque pulses.

A variable valve timing assembly for a combustion engine comprises: a phaser configured to receive therein a camshaft; wherein the phaser includes a phaser exterior body that is cylindrical-shaped, a phaser interior body that is cylindrical-shaped and within the phaser exterior body, a phaser exterior spline on an exterior of the phaser exterior body, and a phaser interior spline on an exterior of the phaser interior body; a phaser inner housing disposed within the phaser and configured to receive therein the camshaft; wherein the phaser inner housing includes an inner housing interior spline that mates with the phaser interior spline; an advancing chamber configured to receive fluid from and discharge fluid to the camshaft; a retarding chamber configured to receive fluid from and discharge fluid to the camshaft; and a main housing that encloses therein the phaser and the phaser inner housing, and is configured to engage a timing chain/belt.

A cam phasing control motor assembly, including: an electric motor with a hollow drive shaft; an actuating pin passing through the hollow drive shaft; an engagement feature; and a displacement assembly. For a camshaft locking mode: the displacement assembly displaces the actuating pin in a first axial direction to non-rotatably connect the engagement feature with a bolt non-rotatably connected to a camshaft; and the camshaft is arranged to non-rotatably connect to an input gear for a gearbox phasing unit, the input gear arranged to receive torque from an engine. For a phase adjusting mode: the displacement assembly displaces the actuating pin in a second axial direction, opposite the first axial direction, to disconnect the engagement feature from the bolt; and the camshaft is arranged to rotate with respect to the input gear.

A camshaft may include a shaft as well as a sliding element that is disposed on the shaft such that the sliding element is axially displaceable along a shaft axis. The shaft may comprise an external tooth for transmitting torque between the shaft and the sliding element. The external tooth may engage a mating tooth geometry formed in a passage of the sliding element. The sliding element on its axial end faces may comprise bearing collars that with the shaft form radial supporting bearings of the sliding element on the shaft. Further, the shaft may comprise cylindrical bearing portions for forming the radial supporting bearings, wherein the bearing portions can be configured with a diameter that is smaller than a diameter circumscribed by tips of the mating tooth geometry that protrude into the passage of the sliding element.

A cam phasing control motor assembly, including: an electric motor with a hollow drive shaft; an actuating pin passing through the hollow drive shaft; an engagement feature; and a displacement assembly. For a camshaft locking mode: the displacement assembly displaces the actuating pin in a first axial direction to non-rotatably connect the engagement feature with a bolt non-rotatably connected to a camshaft; and the camshaft is arranged to non-rotatably connect to an input gear for a gearbox phasing unit, the input gear arranged to receive torque from an engine. For a phase adjusting mode: the displacement assembly displaces the actuating pin in a second axial direction, opposite the first axial direction, to disconnect the engagement feature from the bolt; and the camshaft is arranged to rotate with respect to the input gear.