A hydraulic camshaft adjuster for adjusting the control times of gas exchange valves of an engine is provided. A stator is rotatable synchronously with a crankshaft of the engine. A rotor is arranged so as to be rotatable relative to the stator, and is rotatable synchronously with a camshaft. A plurality of ribs are provided on the stator, dividing an annular chamber between the stator and the rotor into a plurality of pressure chambers. A rotor hub and a plurality of blades extend radially outward from the rotor hub, dividing the pressure chambers into two working chambers having different effective directions. An additional connectable pressure booster is provided at least in an effective directly of the hydraulic camshaft adjuster. The pressure booster can boost the rotor when active.

Disclosed is a control device for a multi-cylinder engine having a combustion chamber (19) to which an intake port (16) and an exhaust port (17) are connected. The control device comprises: an intake-side variable valve operating mechanism (71) for controlling a lift timing of two intake valves (21a, 21b) of the intake port (16); an exhaust-side variable valve operating mechanism (72) for controlling a lift timing of an exhaust valve (22a); and an exhaust-side valve operating mechanism (73) for driving an exhaust valve (22b) at a fixed timing. The control device is operable, when executing cylinder deactivation in a low engine load and low engine speed operating range, to cause the exhaust-side variable valve operating mechanism (72) to open the exhaust valve (22a) during downward movement of a piston (14) in a cylinder (18) being subjected to the cylinder deactivation.

The disclosure relates to a hydraulic camshaft phaser for relative rotation between a camshaft and a crankshaft. The camshaft phaser comprising two oppositely acting working chambers to which hydraulic medium pressure can be applied in a controlling manner by means of a hydraulic valve, thereby causing a relative rotation between the camshaft and the crankshaft. A volume accumulator formed by the camshaft phaser collects the hydraulic medium exiting from the working chambers. The volume accumulator is divided into two partial volume accumulators which flank the working chambers in an axial direction and which are connected to one another by a hydraulic medium line which extends axially through the camshaft phaser and is independent of the working chambers.

Apparatus (10) for a hydraulic valvetrain system (90) comprising: a first oil retaining means 5 (12), a second oil retaining means (20) and an oil conveyance means (14, 16) having a first end (18) operably connected to the first oil retaining means (12) and a second end (22) operably connected to the second oil retaining means (20). The second oil retaining means (20) is configured to receive oil from the first oil retaining means (12) via the oil conveyance means (14, 16), the first oil retaining means (12) is configured to receive oil from the oil 10 conveyance means (14, 16) and the oil conveyance means (14, 16) is configured to receive oil from the second oil retaining means (20).

A control valve for a camshaft adjuster for an engine is provided. The control valve includes a valve sleeve having one or more inlet openings, two supply openings, and an outlet opening, and a control piston guided in the valve sleeve. The piston, together with the valve sleeve and control edges arranged on the control piston, form three annular ducts. A fluid-conducting connection between an inlet opening and a supply opening can be controlled via a first annular channel. A fluid-conducting connection between the inlet opening and another supply opening can be controlled via a second annular channel. The first annular channel and the second annular channels may enclose a central annular channel, via which a fluid-conducting connection between the supply opening and the outlet opening, as well as between the another supply opening and the outlet opening, can be controlled.

A variable valve timing control device includes a drive-side rotational body, a driven-side rotational body, a connecting bolt being coaxially disposed with a rotary axis and connecting the driven-side rotational body to a camshaft, a valve unit including a spool being disposed at an inner space of the connecting bolt and supplying and discharging a fluid to and from an advanced-angle chamber and a retarded-angle chamber, the valve unit discharging the fluid from an opening of a head portion of the connection bolt when the spool controls the fluid, and a reservoir being coaxially disposed with the rotary axis that is positioned laterally, the reservoir accumulating the fluid discharged from the opening of the head portion from which the fluid is configured to be sucked.

A camshaft adjuster including a stator, a rotor and a pressure medium supply, at least one chamber being formed on the stator, which is divided into two working chambers by at least one vane formed on the rotor or rotatably fixedly connected to the rotor is provided. A pressure medium is applicable to each of the two working chambers via the pressure medium supply in such a way that a pressure of the pressure medium may be increased in each of the working chambers to the extent that the pressure increase results in a rotation of the rotor. A switchable valve is formed in the vane of the rotor, which, in a first switching position of the valve, allows a flow of the pressure medium from a first working chamber through the vane into a second working chamber, in a second switching position the valve hydraulically separating the working chambers from each other. A locking element, which fixes the vane in a defined position with respect to the chamber, is designed to control an inflow or outflow of the pressure medium into or out of a working chamber. The pressure medium supply includes an oil pump, a supply line connecting the oil pump to at least one of the working chambers and a hydraulic accumulator, which differs from the oil pump and the supply line.

A hydraulically variable gas exchange valve train for an internal combustion engine is proposed that includes a hydraulic housing with a pressure chamber, a pressure relief chamber, and a vent duct. The vent duct is connected hydraulically on a housing inner side via a restriction to the pressure relief chamber, and opens on the housing outer side below the pressure relief chamber with regard to a direction of gravity. The vent duct opens into a hydraulic reservoir, wherein the vent duct opening lies below a normal level of the hydraulic reservoir with regard to the direction of gravity.

An oil reservoir for a variable camshaft phaser, comprising a locking cover including a front surface including a pool, the pool having a plurality of through-bores, a rear surface including a locking pin channel, a radially inward facing surface, and a radially outward facing surface, and an oil reservoir cover secured to the front surface of the locking cover.

A phase-shifting device, a so-called cam phaser, is arranged between a crankshaft and at least one camshaft to change the at least one camshaft's rotational position in relation to the crankshaft and thus push forward or defer at least one inlet valve's and/or at least one exhaust valve's opening and closing time. The phase-shifting device is connected to an accumulator that can be charged by an oil pump. The oil pressure may be increased with the help of a pressure medium controlled cylinder before or during a phase-shifting process.