A bushing member includes: a large diameter portion which is inserted on a radially inner side of a coiled segment of an assist spring and includes a straight portion which extends in an axial direction; and a small diameter portion which is located on a radially inner side of a housing and has an outer diameter that is smaller than an outer diameter of the large diameter portion. The coiled segment includes a contact portion that contacts the straight portion at a radially inner surface of the contact portion. In an axial direction, a location of an end of the straight portion, which is located on one axial side where a driven shaft is placed, coincides with a location of an end of the contact portion located on the one axial side, or is on the one axial side of the location of the end of the contact portion.

A bushing member includes: a large diameter portion which is inserted on a radially inner side of a coiled segment of an assist spring and includes a straight portion which extends in an axial direction; and a small diameter portion which is located on a radially inner side of a housing and has an outer diameter that is smaller than an outer diameter of the large diameter portion. The coiled segment includes a contact portion that contacts the straight portion at a radially inner surface of the contact portion. In an axial direction, a location of an end of the straight portion, which is located on one axial side where a driven shaft is placed, coincides with a location of an end of the contact portion located on the one axial side, or is on the one axial side of the location of the end of the contact portion.

An oil pressure actuated or torsion assisted phaser with a lock pin that has a position which shuts off communication between the advance and retard chambers and the front cam bearing and/or oil control valve, effectively acting as a shutoff valve and preventing leakage of oil from the advance and retard chambers. The prevention of leakage maintains oil in the phaser after engine shutdown. Additionally, by shutting off communication between the advance and retard chambers and the oil supply, the side load on the lock pin from the oil pressure torque on the rotor vanes during unlocking of the lock pin can be reduced or eliminated.

A phaser which has an offset or remote pilot valve added to the hydraulic circuit to manage a hydraulic detent switching function, in order to provide a mid-position lock for cold starts of the engine, either during cranking or prior to complete engine shutdown. The mid-position locking of the phaser positions the cam at an optimum position for cold restarts of the engine.

A camshaft phase adjuster, which includes first and second oil holes and a locking pin hole formed in the rotor inner core, the first oil hole connecting an engine fluid passage and the first chamber, the second oil hole connecting the first and second chambers, and the first and second oil holes both passing through the locking pin hole. The locking pin is switchable between first and second positions. A one-way valve is provided at the second oil hole; when the locking pin is in the first position, the first oil hole is unblocked, the one-way valve is switched off and the second oil hole is blocked; and in the second position, the first oil hole is blocked, the one-way valve is switched on, and the second oil hole is unblocked. This allows an intermediate locking function.

A hydraulic oil control valve is coaxially disposed with a rotational axis of a valve timing adjustment device for adjusting valve timing of a valve. The valve is selectively opened or dosed by a drive shaft receiving a driving force from a drive shaft. The hydraulic oil control valve includes a tubular sleeve and a spool that is slidably moved within the sleeve. The sleeve includes an inner sleeve and an outer sleeve that is fixed to an end portion of one of the drive shaft and the driven shaft with an axial force. When the axial force is not applied, a minimum clearance between the outer sleeve and the inner sleeve in a radial direction is larger than a minimum clearance between the inner sleeve and the spool in the radial direction.

A hydraulic oil control valve is coaxially disposed with a rotational axis of a valve timing adjustment device. The hydraulic oil control valve includes a sleeve, a spool, a movement restricting portion, a fixing member. The sleeve includes an inner sleeve and an outer sleeve. The fixing member is fixed to an end portion of the outer sleeve facing the actuator. The fixing member is configured to restrict the inner sleeve from moving in a circumferential direction relative to the outer sleeve and to restrict the inner sleeve and the spool from coming off from the outer sleeve toward the actuator in the axial direction.

A camshaft phaser includes an input member and an output member. A valve spool is moveable along an axis between an advance position and a retard position and includes a valve spool bore. A check valve within the valve spool bore includes a check valve member which moves between a seated position and an unseated position such that the check valve member prevents fluid flow out of the valve spool bore through a passage and such that the check valve member permits flow into the valve spool bore through the passage. An insert within the valve spool bore supports the check valve closes one end of the valve spool bore and abuts an insert retainer to retain the insert within the valve spool bore. A spring urges the insert toward the insert retainer and holds the insert retainer in compression against the insert retainer.

An internal combustion engine includes exhaust-side and intake-side variable valve timing mechanisms, an oil passage defined in the cylinder head, an exhaust-side connection passage that branches from the oil passage to conduct oil to the exhaust-side variable valve timing mechanism, and an intake-side connection passage that branches from the oil passage to conduct oil to the intake-side variable valve timing mechanism. The connection passage that conducts oil to one of the exhaust-side variable valve timing mechanism and the intake-side variable valve timing mechanism that has a greater amount of oil leakage when oil having the same pressure is supplied to the variable valve timing mechanisms to operate the variable valve timing mechanisms is located at a downstream side in the oil passage of the connection passage that conducts oil to the variable valve timing mechanism that has a smaller amount of oil leakage.

A sleeve for a cam phaser, wherein the sleeve is arranged between a central valve and a rotor of the cam phaser, wherein the rotor is rotatable relative to a stator of the cam phaser about a rotation axis of the rotor, wherein a vane of the rotor is arranged positionable between two bars of the stator, wherein the vane divides an intermediary space that is formed between the two bars into a first pressure chamber and a second pressure chamber, wherein the rotor is movable by pressures that are provided in the first pressure chamber and in the second pressure chamber, wherein the central valve is configured to provide pressure loading and pressure relief of the first pressure chamber and the second pressure chamber.