Schaeffler Technologies Ag & Co .kg

Oliver Witter

Oliver Schnell

Peter Sailer

Ladislaus Dobrenizki

Michael Kress

Edgar Schulz

Serge Kursawe

Stefan Dupke

Ricardo Henrique Brugnara

Holger Pätzold

Klaus Feldner

Frank Schlerege

Klaus Tietzel

This disclosure relates to a hydraulic support element for a switchable rocker arm of a valve train of an internal combustion engine. The hydraulic support element includes a cup-shaped cylinder, within which a hollow piston is arranged in an axially displaceable manner. The piston includes a filter cartridge which is in the form of a hollow body and can be charged from the outside with pressurized oil and an interior space of which is connected to an outlet opening of the contact head. An interior space of the piston has two pressurized oil chambers, including a first pressurized oil chamber above the piston head and connected to a first pressurized oil feed, and a second pressurized oil chamber formed under the contact head and connected to a second pressurized oil feed. The filter cartridge is tubular and located in the second pressurized oil chamber.

Hydraulic support element

A layer system includes at least one bonding layer and a plurality of functional layers arranged on the at least one bonding layer. Each functional layer has a first nanolayer of a first metal nitride with a first metal constituent, and a metallic second nanolayer. Each functional layer has a layer thickness d in a range of 1 to 100 nm.

Layer system and component

A method for producing a reduced friction sliding surface on a machine element includes applying a coating comprising amorphous carbon to a surface of the machine element and locally heating the coating with a laser. The coating is heated to a temperature below an evaporation temperature of the coating to achieve a local volumetric increase in the coating and a local increase in a layer thickness of the coating. A surface structure of the coating includes a multiplicity of elevations resulting from a local phase transformation of the coating from amorphous carbon into graphite due to the locally heating.

Method for producing a sliding surface

A lever-type cam follower for a valve train of an internal combustion engine, the cam follower having two side walls which are connected to each other through a crossbar on whose underside, on one end, a support for a gas exchange valve is disposed, the crossbar having a recess through which a roller extends, the roller is supported via a bearing on a pin seated in the side walls, wherein the roller is so narrow that outer front ends of the roller are clearly spaced from and out of contact with longitudinal surfaces of the recess, one guide extension projects from each of the longitudinal surfaces towards a central longitudinal plane of the cam follower, and the roller is guided on inner sides of the at least one guide extension.

Cam follower

A valve drive of an internal combustion engine, having a finger lever which acts at one end on a gas exchange valve and which is seated at the other end on a head of a housing of a support element, which housing runs in an axially movable manner in a reception bore of a cylinder head, the finger lever is acted on by a cam from the base circle from which there projects in a fixed manner an additional cam piece for generating an additional lift of the gas exchange valve, a bore extends from a bottom of the housing in the direction of the head, in the lower portion of which bore there runs a pressure piston which is axially movable relative to the housing and via the lower face of which the support element is mounted on a base of the reception bore of the cylinder head, a high-pressure chamber for hydraulic medium is formed between an upper face of the pressure piston and a ring part situated above said upper face and which is fixed with respect to the housing, and to generate the additional lift, the high-pressure chamber is flooded with hydraulic medium such that the housing is deployed relative to the pressure piston, supported on the hydraulic medium column accumulated in the high-pressure chamber, and to deactivate the additional stoke, the hydraulic medium in the high-pressure chamber is discharged such that the housing is retracted.

Valve drive with additional lift in the cam base circle

An internal combustion piston engine based on a four-stroke process, including a crankcase in which at least one cylinder/piston assembly is arranged, the piston being guided by a connecting rod connected to a crankshaft. At least one cylinder head closes the cylinder, each of whose intake and exhaust channels are controlled by at least one intake valve and one exhaust valve (). The intake and exhaust valves () are actuable by a rocker arm () or a finger lever driven by a camshaft () through intake and exhaust cams (). The rocker arms or finger levers are guided on at least one axle (). A brake control device is provided which includes, in the region of the base circle of the exhaust cam (), at least one additional cam () for an additional opening of at least one of the exhaust valves (). A control element () is installed between the rocker arm () or finger lever and the exhaust valve or valves (), which control element () can be connected to the pressurized oil circulation system of the internal combustion piston engine and whose length can be varied, so that the additional cam () is active during a braking operation and inactive during a pure engine operation. The control element (2) is arranged in a bridge () that is associated with a plurality of exhaust valves ().

Growing community of inventors

Westhausen, Germany

Oliver Witter