A spool is configured to reciprocate at an inside space of a sleeve and includes: a spool tube; a spool cover, which closes an end portion of the spool tube located on a camshaft side; a pressure accumulation space, which is formed at an inside of the spool tube; a supply passage, which is configured to connect between the pressure accumulation space and a supply port; a control passage, which is configured to connect between the pressure accumulation space and a primary control port; and a control passage, which is configured to connect between the pressure accumulation space and a secondary control port. A variable volume space is formed between the spool cover and a sleeve bottom. The sleeve includes a breathing hole at an outside of the inside space while the breathing hole is a hole that communicates between the variable volume space and the atmosphere.

A camshaft adjusting system (1) is provided for a first camshaft (2) and a second camshaft (3) which are arranged concentrically with respect to one another, the second camshaft (3) being arranged within the first camshaft (2). A vane-cell type hydraulic camshaft adjuster (4) is configured for adjusting the first camshaft (2) and an electric camshaft adjuster (5) is configured for adjusting the second camshaft (3). A front cover (7) which is fastened to a stator (6) of the hydraulic camshaft adjuster (4) and which closes off the camshaft adjuster (4) at a side facing away from the camshaft has an internal toothing (8) for supporting a flex pot (9) which is attached to the second camshaft (3) and which is designed for receiving torque from the electric camshaft adjuster (5). A camshaft adjusting unit having the camshaft adjusting system (1) and two camshafts (2, 3) is also provided.

The disclosure relates to a hydraulic camshaft adjuster for the variable adjustment of the control times of gas exchange valves of an internal combustion engine, having a stator and a rotor rotatable relative to the stator. Radially inwardly projecting webs are formed on the stator and radially outwardly projecting vanes are formed on the rotor. Between the stator and the rotor are formed several hydraulic working chambers, each of which is divided into a first working chamber and a second working chamber by a vane of the rotor. Two locking elements are inserted into the rotor for the temporary, reversibly detachable fixing of the rotor relative to the stator in a middle position. The first locking element and the second locking element can be locked in a common locking slotted guide. The disclosure also relates to a method for locking of the rotor in such a hydraulic camshaft adjuster.

A cam phaser mechanism includes an inner ring (rotor), and outer ring (stator), and a face plate. The inner ring that is wider than outer ring. The face plate is contoured such that it is thinner in a region in contact with the inner ring and thicker in a region in contact with the outer ring, thus compensating for the different widths of the inner ring and outer ring. The stator is fastened to the face plate by a plurality of bolts which are threaded into the face plate. The greater width of the face plate in this region provides sufficient thread engagement without increasing the overall width of the cam phaser mechansim.

When a supply check valve is opened, the supply check valve enables a flow of oil from an oil supply source toward a pressure accumulation space. When the supply check valve is closed, the supply check valve limits a flow of the oil from the pressure accumulation space toward the oil supply source. When a recycle check valve is opened, the recycle check valve enables a flow of the oil from a retard chamber or an advance chamber toward the pressure accumulation space. When the recycle check valve is closed, the recycle check valve limits a flow of the oil from the pressure accumulation space toward the retard chamber or the advance chamber. A characteristic of the supply check valve with respect to valve opening of the supply check valve is different from a characteristic of the recycle check valve with respect to valve opening of the recycle check valve.

A hydraulic camshaft adjuster adjusts the control time of gas exchange of an internal combustion engine. A reservoir for storing pressure medium is formed on a cover of the hydraulic camshaft adjuster. An overflow opening of the cover is dimensioned such that a volume of pressure medium remains in the reservoir when the hydraulic camshaft adjuster is stationary. This ensures that pressure medium is supplied to the return valve of a central locking mechanism when the engine is running.

The disclosure relates to a hydraulic camshaft adjuster having a stator, which is synchronously rotatable with a crankshaft of the internal combustion engine, a rotor rotatably arranged relative to the stator and synchronously rotatable with a camshaft, two groups of working chambers that can each be loaded with a pressure medium in a pressure medium circuit, and a central locking device for locking the rotor in a defined position relative to the stator. The stator is delimited on a first front end by a multi-part locking cover. The multi-part locking cover has a first locking cover and a second locking cover. A first stage of a mechanical ratchet is formed on the first locking cover, and at least one further stage of the mechanical ratchet is formed on the second locking cover.

This disclosure relates to a camshaft adjusting system for a motor vehicle, having an inner camshaft, and an outer camshaft, which is arranged coaxially with and radially outside the inner camshaft. The camshaft adjusting system further includes an input wheel, which is designed to introduce torque into the camshafts, a hydraulic camshaft adjuster, which acts on the outer camshaft to adjust the phase angle of the outer camshaft relative to the input wheel, and an electric camshaft adjuster, which acts on the inner camshaft to adjust the phase angle of the inner camshaft relative to the input wheel. The electric camshaft adjuster engages in the hydraulic camshaft adjuster at least partially in an axial direction.

An internal combustion engine valve timing control device includes a communication passage formed in a first rotating member to communicate with a working chamber, and including a first opening. The first opening is opened to a back pressure chamber when a tip portion of a lock member is inserted in a lock hole, and is closed by the lock member when the tip portion of the lock member is out of the lock hole. A first cross-sectional area is smaller than a second cross-sectional area, wherein the first cross-sectional area is a smaller one of a minimum cross-sectional area of the communication passage and an open cross-sectional area of the first opening, and the second cross-sectional area is a smaller one of a minimum cross-sectional area of an exhaust passage and an open cross-sectional area of an opening of the exhaust passage opened to the back pressure chamber.

A camshaft phaser includes a stator defining a cavity and configured to receive power from an engine crankshaft. The phaser further includes a rotor supported within the cavity and rotatable relative to the stator. The rotor has a first face, a second face, and a first hole extending from the first face to the second face. A target wheel of the phaser has a plate portion configured to be read by a camshaft-position sensor and a hub portion seated on the first face. The hub portion defines a second hole that is aligned with the first hole. A pin extends through the first and second holes to rotationally align and secure the target wheel to the rotor.