A system including a phaser with a first lock pin and a second lock pin in the rotor assembly. The first and second locks pins having a locked position where they engage a recess in the housing assembly and an unlocked position in which they do not engage the housing assembly. The first lock pin locks the rotor assembly to the housing assembly when the phaser is in or near an intermediate phase angle position. The second lock pin locks the rotor assembly to the housing assembly when the phaser is at a full retard position. Alternatively, the second lock pin can lock the rotor assembly to the housing assembly when the phaser is at a full advance position. The second lock pin is spring biased towards the unlocked position and is pressurized to engage and move to the locked position by either the advance or the retard chamber.

A hydrostatic camshaft phaser system includes a hydraulically-actuated camshaft phaser with a rotor; and a stator housing that receives the rotor and includes an advancing chamber and a retarding chamber defined at least partially by the vane; and a variable displacement pump, in fluid communication with the hydraulically-actuated camshaft phaser, comprising a first chamber in fluid communication with the advancing chamber and a second chamber in fluid communication with the retarding chamber; the first chamber receives fluid from a first non-continuous groove extending along a camshaft surface or a bearing surface and the second chamber receives fluid from a second non-continuous groove extending along the camshaft surface or the bearing surface during a first portion of camshaft rotation, and the first chamber receives fluid from the second non-continuous groove and the second chamber receives fluid from the first non-continuous groove during a second portion of camshaft rotation.

A valve opening/closing timing control device includes: a driving side rotator synchronously rotating with a crankshaft of an internal combustion engine; a driven side rotator coaxially disposed with a rotation axis of the driving side rotator and integrally rotating with a valve opening/closing camshaft; advance and retard chambers formed between the driving side and driven side rotators; a lock mechanism including a lock member capable of engaging with a recessed portion formed on one of the driving side and driven side rotators, and provided in the other of the driving side and driven side rotators; and a connecting bolt coaxially disposed with the rotation axis and connecting the driven side rotator to the camshaft, in which the connecting bolt includes an internal space, a valve unit accommodates a spool, and the spool includes an internal flow path, and, in the spool, a lock holding check valve is disposed.

In a valve timing control system, a control command unit includes: a first stage setting block and a next stage setting block. The first stage setting block sets a retard holding command value as a control command value to introduce hydraulic fluid to each retard operation chamber under a state where a rotation phase is locked, to start applying an operation pressure more than or equal to an unlock pressure to a lock component. The next stage setting block sets an advance holding command value as a control command value to introduce hydraulic fluid to each advance operation chamber, after setting the retard holding command value, to maintain the applying of the operation pressure more than or equal to the unlock pressure to the lock component.

A variable valve timing control device includes a valve unit including a spool having a plurality of land portions at an outer circumference of the spool, and being formed with a drain flow path inside the spool. The valve unit allows a second pump port and a lock port to communicate with each other in a case where the spool is set at an unlock position where a lock state of a lock mechanism is released, and the valve unit closes the second pump port with the land portion of the spool and allows the lock port to communicate with the drain flow path in a case where the spool is set at a lock position where the lock mechanism is allowed to be shifted in the lock state.

A method for cleaning a continuously variable valve timing (CVVT) system for removing foreign materials includes: switching a target operating value of the CVVT system to a predetermined setting value within a set operating region and performing cleaning of the CVVT system; and determining whether a valve timing control learning request exists for the CVVT system, and, when the valve timing control learning request exists, aborting the cleaning.

A valve opening and closing timing control apparatus includes a driving-side rotating body, a driven-side rotating body fixed to a camshaft by a bolt, a fluid pressure chamber, an intermediate lock mechanism, a lock flow passage bringing the working fluid to the intermediate lock mechanism, and an electromagnetic valve including a spool which is arranged at an inner portion of the bolt, the lock flow passage including a first flow passage which is arranged between the spool and a supply flow passage in a radial direction and which is connected to the supply flow passage, the lock flow passage including a second flow passage which is provided at the inner portion of the bolt in a penetrating manner in the radial direction and which brings the working fluid to flow between the spool and the intermediate lock mechanism.

In a hydraulically-operated vane rotor equipped variable valve timing control device for an internal combustion engine, a fluid-communication control mechanism is configured to switch, after having started the engine, a communication hole from a communicated state to a fluid-communication restricted state prior to switching operation of a lock mechanism from a lock state in which rotary motion of a vane rotor relative to a housing is restricted to an unlock state in which rotary motion of the vane rotor relative to the housing is enabled. As a result of this configuration, it becomes possible to apply, after having started the engine, an appropriately controlled hydraulic pressure to all of vanes, with hydraulic pressure supplied to either all phase-retard chambers or all phase-advance chambers, thereby ensuring a good control responsiveness of the vane rotor.

A vane cell adjuster including a central locking device for locking the rotor in a central locking position, wherein the central locking device has at least two spring-loaded locking pins which can be locked in a stator-fixed locking slotted guide and which, during a rotation of the rotor from the direction of an early or late stop position, lock into the central locking position from different directions in the locking slotted guide, wherein a locking pin forms a valve unit with the respective accommodation chamber, wherein in a first switch position of the valve unit, at least one first pressure medium line is connected to allow free flow to a second pressure medium line, and in a second switch position of the valve unit, the first pressure medium line is connected to allow flow via a check valve to the second pressure medium line, wherein the check valve is provided in the rotor outside of the locking pin.

A camshaft phaser assembly, including: an axis of rotation; a first hydraulic camshaft phaser including a stator arranged to receive rotational torque and including a plurality of radially inwardly extending protrusions, a rotor including a plurality of radially outwardly extending protrusions circumferentially interleaved with the plurality of radially inwardly extending protrusions, and a plurality of phaser chambers, each phaser chamber circumferentially bounded by a respective radially inwardly extending protrusion included in the plurality of radially inwardly extending protrusions and a respective radially outwardly extending protrusion included in the plurality of radially outwardly extending protrusions; a second hydraulic camshaft phaser; a cap; and a fluid chamber bounded in part by the cap and in fluid communication with a phaser chamber included in the plurality of phaser chambers; and a bolt arranged to non-rotatably connect the rotor and the cap to a camshaft.