Patent ID: 7523728

Claim:
A phaser for controlling the timing between a camshaft and a timing gear, the phaser comprising: a rotor having at least one vane, the rotor being connectable to one of the camshaft and the timing gear for rotation therewith; a stator, co-axially surrounding the rotor, provided with at least one recess for receiving the at least one vane of the rotor and allowing rotational movement of the rotor with respect to the stator, the stator being connectable to the other of the camshaft and the timing gear, wherein the at least one vane divides the at least one recess into a first pocket and a second pocket, the first and second pockets being able to receive fluids under pressure, wherein the introduction of a fluid into the first pocket causes the rotor to move in a first rotational direction relative to the stator, and in that the introduction of a fluid in the second pocket causes the rotor to move in the opposite rotational direction relative to the stator; wherein the phaser comprises control means for controlling the fluid pressure on opposite sides of the at least one vane to thereby control the angular position of the rotor with respect to the stator; wherein the control means comprise means for selectively adjusting the timing of the opening and closing of a connection between the first and second pockets in order to allow fluid to flow between the first and second pockets using the pressure difference of the fluid in each of the pockets to transport the fluid from the one to the other pocket; and wherein the means for selectively adjusting comprises first rotor-apertures and second rotor-apertures, positioned on opposite sides of the at least one vane, and a control ring, co-axial with the rotor, wherein the control ring is provided with one or more apertures permitting selective communication between the first and the second rotor-apertures, and a driver for adjusting an angular position of the control ring with respect to a rotational axis of the phaser to adjust the timing of the opening and closing of communication between the first and second rotor-apertures.