There is provided a variable valve timing system, including: a camshaft rotatably supported by a support wall of an engine; a variable valve device configured to advance or retard the camshaft by a hydraulic pressure; and an oil control valve. A thrust stopper is formed on an outer peripheral surface of the camshaft. A bearing surface of the support wall is formed with an advance groove through which oil for advancing the camshaft is to pass, a retard groove through which oil for retarding the camshaft is to pass, and an accommodation groove configured to accommodate the thrust stopper. At the bearing surface, the retard groove is positioned on one wall surface side of the support wall, the accommodation groove is positioned on the other wall surface side of the support wall, and the advance groove is positioned between the retard groove and the accommodation groove.

A hydraulic pump-motor includes a cylinder block including a plurality of fluid chambers, a piston in each of the fluid chambers, a cam, a fixed valve area profile, and a timing adjustment actuator. The cam includes a cam surface that engages the pistons and drives movement of the pistons relative to the fluid chambers in response to relative rotation between the cam and the fluid chambers. The fixed valve area profile is configured to control fluid flows between the fluid chambers and first and second ports. The timing adjustment actuator is configured to adjust an angular orientation of the fixed valve area profile relative to an angular orientation of the cam based on a pressure differential between a pressure at the first port and a pressure at the second port.

The disclosure relates to a camshaft adjusting device with a dry belt, a central valve arranged within a camshaft adjuster, and an actuator acting on the central valve. An oil-tight wet space is formed by the camshaft adjuster and the actuator or a component supporting the actuator, and oil present in the wet space can be evacuated by means of an oil path. A portion of this oil path extends axially through the output element of the camshaft adjuster. This oil path can pass the end-side contact face between the output element and camshaft, opening out into an axial bore of the camshaft which is distanced radially from the axis of rotation of the camshaft adjusting device. The axial bore runs beneath an oil feed connection formed on the outer surface of the camshaft for feeding oil to the central valve.

A hydraulically-actuated variable camshaft timing (VCT) phaser assembly is employed for use in an automotive internal combustion engine. The VCT phaser assembly has a housing, a rotor, a first plate, a second plate, and a control valve. The rotor is situated within the housing, and a plurality of chambers are established between the rotor and housing. The first plate is situated on one side of the housing and rotor, and the second plate is situated on an opposite side of the housing and rotor. One or more air vents reside in one or more of the housing, rotor, first plate, second plate, or control valve. Air separated from hydraulic fluid in the VCT phaser assembly amid use and that makes its way to the air vent(s) can escape the VCT phaser assembly.

There is provided a variable valve timing system including: a variable valve device; an oil control valve configured to control a hydraulic pressure with respect to the variable valve device; an external pipe connecting a main gallery and the oil control valve; and a hydraulic pressure sensor configured to detect a hydraulic pressure in an oil path formed at the crankcase. The oil control valve is disposed on one side surface of the engine in the vehicle width direction. One end portion of the external pipe is connected to one side of the main gallery in the vehicle width direction. In a bottom view of a vehicle, the one end portion of the external pipe overlaps with the crankcase, and the hydraulic pressure sensor overlaps with the crankcase on one side of the one end portion of the external pipe in the vehicle width direction.

There is provided a variable valve timing system, including: a camshaft rotatably supported by a support wall of an engine; a variable valve device configured to advance or retard the camshaft by a hydraulic pressure; and an oil control valve. A thrust stopper is formed on an outer peripheral surface of the camshaft. A bearing surface of the support wall is formed with an advance groove through which oil for advancing the camshaft is to pass, a retard groove through which oil for retarding the camshaft is to pass, and an accommodation groove configured to accommodate the thrust stopper. At the bearing surface, the retard groove is positioned on one wall surface side of the support wall, the accommodation groove is positioned on the other wall surface side of the support wall, and the advance groove is positioned between the retard groove and the accommodation groove.

A hydraulic fluid control valve (HFCV) configured to recirculate an exiting hydraulic fluid from a first hydraulic actuation chamber to a second hydraulic actuation chamber is provided. The HFCV includes a selectively movable spool having an inner fluid chamber configured to receive and deliver the exiting hydraulic fluid to one or both of either a sump or one of the first or second hydraulic actuation chambers.

A hydraulic fluid control valve (HFCV) configured to recirculate an exiting hydraulic fluid from a first hydraulic actuation chamber to a second hydraulic actuation chamber is provided. The HFCV includes a selectively movable spool having an outer annulus configured to receive and deliver the exiting hydraulic fluid to one or both of either a sump or one of the first or second hydraulic actuation chambers.

A valve assembly for controlling an apparatus for camshaft timing adjustment being driven by a hydraulic pump, having a valve body with a first control port, a second control port, a high pressure port and a low pressure port, the valve assembly having a first state for enabling a flow of a hydraulic fluid from the high pressure port to the first control port and from the second control port to the low pressure port, respectively, and a second state for enabling a flow of the hydraulic fluid from the high pressure port to the second control port and from the first control port to the low pressure port, respectively. The valve body has central actuating through-hole extending axially through the valve body defining an axial direction.

A valve opening and closing timing control device includes: a drive-side rotary body rotating synchronously with a crankshaft; a driven-side rotary body arranged coaxially with the drive-side rotary body and rotating integrally with a valve opening and closing camshaft; a fluid pressure chamber defined between the drive-side and driven-side rotary bodies; advance and retard chambers defined by partitioning the fluid pressure chamber; an intermediate lock mechanism selectively switches between a lock state and a lock release state; advance and retard flow paths allowing a flow of the working fluid to be supplied to and discharged from the advance and retard chambers; a control valve including a spool; and a phase control unit moving a position of the spool by controlling a power supply amount to the control valve to supply and discharge the working fluid to and from the advance and retard chambers to displace a relative rotation phase.