Schaeffler Technologies Ag & Co .kg

Hermann Keller

Roland Krapp

Calin Petru Itoafa

The invention proposes a subassembly of a hydraulic variable valve train of an internal combustion engine, having a guide bushing () that can be installed in a hydraulic housing (), and having a piston () supported therein so as to be axially movable for actuating a gas exchange valve (), and having a valve element () that, together with the end face () of the piston distant from the gas exchange valve, defines a hydraulic pressure chamber () in the guide bushing, wherein the valve element is a throttle check valve that allows hydraulic medium to flow out of the pressure chamber throttled by a continuously open throttle opening () and allows hydraulic medium to flow into the pressure chamber with little throttling by a ball check valve (). The subassembly is intended to be implemented as a modular unit assembled outside of the hydraulic housing, wherein the guide bushing and the valve element are fastened to one another, and the piston is secured in a captive manner in the guide bushing.

Hydraulic valve train of an internal combustion engine

A rail used as a torsional stop for the valve train of an internal combustion engine is disclosed. The rail includes spaces () which are arranged in a row spaced apart at a distance from one another within the rail () and accommodate inserted valve lifters provided as roller tappets (). Two parallel torsional stop areas () are configured on the outer surface of each roller tappet () in the form of planar flattened zones in order to secure the roller tappet () against rotation about the central longitudinal axis thereof. The torsional stop areas () rest against guide areas of the rail (), which are located inside the associated accommodating space (). An insertion opening, indicated as a keyhole (), into which the respective roller tappet () is inserted in a direction of the longitudinal axis thereof before being displaced parallel to the axis towards the guide areas of the rail () used as the torsional stop and then once again being moved in the axial direction, is assigned to the accommodating space () of the rail (). A protruding catch is disposed in the area of the recess () of the rail while a radial groove (), which engages around the catch of the rail () when the roller tappet () is displaced parallel to the axis thereof, is incorporated into the roller tappet () in a region of the torsional stop area.

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Lauingen, Germany

Hermann Keller