An apparatus includes a bearing assembly of a first camshaft and a second camshaft on a cylinder head of an internal combustion engine. The first camshaft has a first recess where a tool is insertable into the first recess and the second camshaft has a second recess where the tool is insertable into the second recess. A cylinder head hood is attached to the cylinder head where the cylinder head hood has a first through-opening matched with the first recess and a second through-opening matched with the second recess. A first wall area of the cylinder head hood that at least partially delimits the first through-opening and a second wall area of the cylinder head hood that at least partially delimits the second through-opening are disposed at different heights.

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.

The disclosu rerelates to a shaft adjuster, in particular a camshaft adjuster, comprising a drive gear having a spur gear toothing and a clamping gear which is arranged coaxially relative to the drive gear and which is loaded by a spring acting in the circumferential direction. The spring is also designed as an axial securing element for axially securing the clamping gear on the drive gear .

A harmonic drive (1) comprises three connection elements (2, 9, 13), namely an input element (2), an output element (13) and an adjusting element (9), and an anti-twist mechanism (15) operates between the connection elements (2, 9, 13), the anti-twist mechanism comprising an anti-twist element (18), which is concentric to the connection elements (2, 9, 13) and interlockingly cooperates with one of the connection elements (9) and frictionally cooperates with one other connection element (2).

A fixture assembly includes a primary gage member, camshaft gages, a crankshaft gage and an engine gage, all of which have planar datum surfaces that are each dimensionally located relative to the primary gage member planar datum surface. The engine gage includes an engine datum surface, and is sized and shaped to receive, support and dimensionally locate the engine. An engine block datum surface is configured to be positioned on the engine datum surface thereby locating the engine relative to the primary gage member datum surface. The primary, first, second and engine datum surfaces are fixed in a parallel relationship to each other so as to form a parallel alignment system such that when the fixture assembly datum surfaces engage and form parallel alignment with the corresponding engine datum surfaces, the camshafts and crankshaft are angularly located in a predetermined angular orientation for proper timing of the engine assembly.

A method for mounting a camshaft module may involve a module that includes a module cover in which a camshaft is accommodated. The camshaft may comprise a main shaft and a plurality of displacement elements with cam tracks formed thereon for valve-control purposes. The displacement elements may be arranged at predetermined positions in the module cover. The main shaft may be guided along a shaft axis through accommodating passages of the displacement elements. The method may involve arranging a first displacement element in the module cover, introducing the main shaft into the module cover and guiding the main shaft through the accommodating passage of the first displacement element, arranging a second displacement element in the module cover, rotating the main shaft about the shaft axis by an angular amount, and advancing and guiding the main shaft through the accommodating passage of the second displacement element. Further, the displacement elements are arranged in the model cover with an identical rotary orientation about the shaft axis.

An adjustable camshaft, which can be utilized in a motor vehicle, may include at least one fixed cam arranged rotationally fixed on at least one outer shaft segment and at least one adjusting cam arranged rotationally fixed to an inner shaft extending concentrically within the outer shaft segment. A method for producing such an adjustable camshaft may involve arranging an outer shaft segment on an inner shaft, generating a surface modification on a surface of the inner shaft to generate at least one arranging section, arranging a fixed cam on at least one section of the outer shaft segment, and arranging the adjusting cam on the arranging section of the inner shaft.

An electrically-actuated variable camshaft timing (VCT) phaser is employed for use with an internal combustion engine (ICE). The electrically-actuated VCT phaser includes a gear set assembly and a fixture. The gear set assembly has an input gear and an output gear, among other possible components. The input gear receives rotational drive input from an engine crankshaft, and the output gear transmits rotational drive output to an engine camshaft. The fixture is secured in the gear set assembly. Amid installation of the electrically-actuated VCT phaser on the ICE, the fixture constrains rotational movement of the gear set assembly. After installation, the fixture can be removed from the gear set assembly.

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 system for timing a crankshaft and a camshaft in an internal combustion engine having a cylinder head structure with a timing pin hole and a camshaft cavity. The camshaft has a first opening that extends from an outer annular wall of a first shaft towards a longitudinal axis. A cam bushing having a bushing clearance hole is inserted into the camshaft cavity and the camshaft is assembled with the cam bushing and cylinder head structure to align the bearing clearance hole with first opening of the camshaft. A timing pin is inserted through the timing pin hole, bushing clearance hole, and first opening of the camshaft to position the camshaft in a camshaft timing position. The crankshaft is rotated to a crankshaft timing position either before or after the camshaft is rotated for setting a static timing of the crankshaft and camshaft, and the timing pins are removed.