Schaeffler Technologies Ag & Co .kg

Ina Schaeffler Kg

Jochen Tovar

Peter Sailer

Oliver Schnell

Wolfgang Christgen

Michael Kugler

Max Schafer

Jürgen Kretschmer

Max SCHÄFER

A double-flow hydraulic support element for a switchable finger lever of a valve train of an internal combustion engine is provided. A piston is arranged in an axial bore of the housing of the support element in an axially movable manner, and the piston includes a hollow cylindrical pressure part and a cup-shaped working part. A head of the pressure part is used as a support for the finger lever and projects beyond the housing edge, and an opening for the flow of a hydraulic medium is formed in the end face of the head. The housing has a first passage and a second passage axially spaced from the first passage for the hydraulic medium. The support element has a hydraulic play compensation device with a ball non-return valve for the finger lever. In order to achieve an optimal actuation of the coupling element, a sleeve which is closed on one side is inserted into the pressing part; the closed end of the sleeve reaches the region of an outer annular groove in a sealing manner below the dome-shaped head of the pressing part; a storage space for supplying the play compensation device with the hydraulic medium is formed radially within and axially outside of the sleeve, in the pressure part, and in the working part of the piston; the storage space is connected to the first passage in the housing via a passage opening in the working part; an actuation space formed between the sleeve and the pressure part of the piston for hydraulically supplying the coupling device is connected to the second passage in the housing via a radial passage opening in the pressure part; and the volume of the storage space is substantially greater than the volume of the actuation space.

Support element

A switchable valve drive element of an internal combustion engine can be actuated hydraulically. A valve tappet which can be displaced axially in a bore of the machine housing by the cam of a camshaft. A switching duct adjoins the valve tappet and is filled with a hydraulic oil. A connection on the valve drive element between the switching duct and a space with a lower pressure level compared to the pressure in the switching duct. The connection can be produced between the switching duct and the space with a lower pressure level by means of the valve tappet. The space may be inside the tappet.

Switchable valve drive element of an internal combustion engine

A valve timing mechanism of an internal combustion engine of a motor vehicle, having a camshaft having at least one cam (), via which a switchable valve timing mechanism element () can be loaded with a cam stroke (s), in which locking means () are arranged on the valve timing mechanism element (), which locking means () have a locking play () which is active in the direction of a valve stroke, in which the cam () has a base circle region (&#x3b1;) and a ramp region () with an opening ramp (&#x3b3;) which adjoins the base circle region (&#x3b1;), and in which at least one ramp section () is formed on the opening ramp (&#x3b3;) in order to compensate for the locking play (). In order to provide a valve timing mechanism of an internal combustion engine, which produces sufficient idle travel of a locking play () of the switchable valve timing elements () being loaded by the cam ramps of the cams (), and nevertheless manages with a relatively short length of the cam ramps, the cam () is shaped in the locking play ramp section () for compensating for the locking play () in such a way that, during a run-off movement over a cam counterelement () of the valve timing mechanism element (), in the event of a rotation of the camshaft, it runs off with an increased cam velocity (v) in comparison with adjacent ramp sections (), at least in one part of the locking play ramp section ().

Valve timing mechanism of an internal combustion engine

A switchable cam follower, comprising two relatively movable, e.g., telescopable, units which can be connected via a coupling which engages over a dividing face between the units such that there is a large valve stroke. It is possible to generate no valve stroke or a small valve stroke if the coupling does not engage. At least one spring, which can be loaded compressively or torsionally, acts as a lost motion spring between the units. A compression limiting device impedes movement of the lost motion spring to the blocked position. In an incorrect switching operation in which the coupled units move undesirably toward each other and in a sudden manner under the influence of a valve spring force, movement of the spring into the 'blocked' position to become seated is prevented by the limiting device.

Growing community of inventors

Erlangen, Germany

Jochen Tovar