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 mechanical cam phasing includes a stator, a cradle rotor, a first locking mechanism having a first locking feature and a second locking feature, a cage, and a second locking mechanism rotationally coupled to the cradle rotor and selectively moveable between a locking state and a phasing state. In the locking state, a clearance is provided between the cradle rotor and the cage to allow the cradle rotor to rotate relative to the cage and lock the first locking feature or the second locking feature. In the phasing state, the clearance between the cradle rotor and the cage is reduced to ensure rotational coupling between the cradle rotor and the cage in at least one direction, which displaces the first locking feature or the second locking feature relative to the cradle rotor and enables the cradle rotor to rotate relative to the stator.

A mechanical cam phasing system includes a stator, a cradle rotor, a first locking mechanism having a first locking feature and a second locking feature, a cage, and a second locking mechanism rotationally coupled to the cradle rotor and selectively moveable between a locking state and a phasing state. In the locking state, a clearance is provided between the cradle rotor and the cage to allow the cradle rotor to rotate relative to the cage and lock the first locking feature or the second locking feature. In the phasing state, the clearance between the cradle rotor and the cage is reduced to ensure rotational coupling between the cradle rotor and the cage in at least one direction, which displaces the first locking feature or the second locking feature relative to the cradle rotor and enables the cradle rotor to rotate relative to the stator.

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.

Systems and methods for varying a rotational relationship between a cam shaft and a crank shaft on an internal combustion engine (i.e., cam phasing) are provided. In particular, systems and methods are provided that facilitates a rotary position of a first component to be accurately controlled with a mechanism causing a second component, which can be coupled to the cam shaft or crank shaft, to follow the rotary position of the first component.

A mechanical cam phasing includes a stator, a cradle rotor, a first locking mechanism having a first locking feature and a second locking feature, a cage, and a second locking mechanism rotationally coupled to the cradle rotor and selectively moveable between a locking state and a phasing state. In the locking state, a clearance is provided between the cradle rotor and the cage to allow the cradle rotor to rotate relative to the cage and lock the first locking feature or the second locking feature. In the phasing state, the clearance between the cradle rotor and the cage is reduced to ensure rotational coupling between the cradle rotor and the cage in at least one direction, which displaces the first locking feature or the second locking feature relative to the cradle rotor and enables the cradle rotor to rotate relative to the stator.

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.

A variable valve timing control device includes a connection mechanism provided with a coupling member which connects a driving-side rotation member and an input gear with each other, the connection mechanism including a first engagement portion and a second engagement portion, the first engagement portion engaged with the driving-side rotation member so as to be relatively displaceable therewith in a first radial direction, the second engagement portion engaged with the input gear so as to be relatively displaceable therewith in a second radial direction which is orthogonal to the first radial direction, and a biasing member restricting a coupling member from being displaced.

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.

An engine variable camshaft timing phaser (10) includes a sprocket (12) and a planetary gear assembly (14). The sprocket (12) receives rotational drive input from an engine crankshaft. The planetary gear assembly (14) includes two or more ring gears (26, 28), multiple planet gears (24), a sun gear (22), and a wrap spring (76). One of the ring gears (26, 28) receives rotational drive input from the sprocket (12) and one of the ring gears (26, 28) transmits rotational drive output to an engine camshaft. The sun gear (22) engages with the planet gears (24). The wrap spring (76) experiences expansion and contraction exertions to permit advancing and retarding engine valve opening and closing, and to prevent advancing and retarding engine valve opening and closing.