A hydraulic camshaft adjuster (1), in which the locking system (7, 8) includes a first and a second control element (7, 8). In order to approach the middle position easily, the first control element (7) has a first and a second switching position, wherein in the first switching position a fluidic connection between the hydraulic pump (P) and a first of the two sub-chambers (B) and a fluidic connection between the other, second sub-chamber (A) and the tank (T) can be established, and in the second switching position a fluidic connection between the hydraulic pump (P) and the second of the two sub-chambers (A) and a fluidic connection between the other, first sub-chamber (B) and the tank (T) can be established, and the second control element (8) is free from different switching positions and has no influence on the flow of hydraulic fluid.

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 spring well that combines a hydraulic fluid received from a hydraulic fluid pressure source with a recirculated hydraulic fluid from the first hydraulic actuation chamber and delivers the combination to the second hydraulic actuation chamber.

A valve timing adjustment device includes: a housing member; a vane rotor that includes vanes and is securely coupled to a driven shaft and is rotatable relative to the housing member when the vane rotor receives a pressure of hydraulic oil introduced into hydraulic chambers; a fixing member that fixes the vane rotor to the driven shaft; and a bearing section that rotatably supports the housing member. The housing member includes a winding section that is formed at an outer peripheral surface of the housing member. A transmission member is wound around the winding section. The bearing section and the winding section at least partially overlap with each other when viewed in a direction perpendicular to an axial direction.

A camshaft phaser routes pressurized fluid from a set of chambers that are decreasing in volume to a reservoir. Oscillations of the rotor with respect to the stator create intervals in which the pressure in the reservoir exceeds the pressure in the set of chambers which are increasing in volume. During these intervals, fluid flows from the reservoir, through one-way valves, into the chambers which are increasing in volume. Pressurization of the reservoir increases the volume of flow through the one-way valves, decreasing the pump flow requirement for the camshaft phaser.

A camshaft phaser, including: a stator arranged to receive rotational torque, including a plurality of radially inwardly extending protrusions, and supported for rotation around an axis of rotation; a rotor including a plurality of radially outwardly extending protrusions circumferentially interleaved with the plurality of radially inwardly extending protrusions, and arranged to non-rotatably connect to a camshaft; a plurality of phaser chambers, each phaser chamber circumferentially bounded by a radially inwardly extending protrusion included in the plurality of radially inwardly extending protrusions and a radially outwardly extending protrusion included in the plurality of radially outwardly extending protrusions; an annular washer; and a target wheel including a first portion axially located between the annular washer and the rotor and in contact with the annular washer, arranged to detect a rotational position of the rotor for use in rotating the rotor with respect to the stator.

A device for controlling a camshaft phaser includes a hydraulic element with a body, a slide assembly having a slide body, and a valve assembly with a first valve, a second valve, and a third valve. The device also includes an actuator which moves along a longitudinal axis between 1) a first position in which the first valve opens or closes a first fluid communication, 2) a second position in which the second valve and the tray open or close a second fluid communication, and 3) a third position in which the third valve and the slide body open or close a third fluid communication between a retard port and a retard chamber.

A check valve for controlling the flow of a fluid into a variable camshaft timing phaser.

A variable cam timing phaser includes a housing disposed about an axis and having an inner housing surface defining a housing interior. The variable cam timing phaser includes a rotor moveable between an advance position and a retard position. The rotor includes a hub and a vane, with the rotor and the housing defining a chamber. The vane further defines the chamber into an advance chamber and a retard chamber. The variable cam timing phaser also includes a control valve assembly including a valve housing and a control piston. The variable cam timing phaser also includes a chamber biasing assembly disposed in one of the advance and the retard chambers and configured to bias the rotor into a predetermined position between the advance and the retard positions. The chamber biasing assembly includes a chamber piston, a chamber biasing member, and a chamber check valve.

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 control screw for a camshaft phase shifter of an internal combustion engine extends along a longitudinal axis. The control screw includes a screw body. The control screw also includes a tubular spool assembly having a control valve assembly with at least three rigid rings and at least two valves. Each valve includes at least one vane connected to two flexible arms. The valve is connected to two consecutive rigid rings.