Ina Schaeffler Kg

Ina Walzlager Schaeffler Ohg

Henning Karbstein

Michael Haas

Mario Kuhl

Dieter Schmidt

Martin Rauch

Walter Speil

Norbert Nitz

Lothar Von Schimonsky

Jason Morehead

Alfred Borst

A switchable cam follower () or a switchable support element of a valve train of an internal combustion engine, said cam follower or support element comprising an outer part () which is assembled together with an inner part () that is displaceable relative thereto in a direction of cam lift, said inner part () comprising, at a parting gap () to the outer part (), two spaced apart or opposing openings () for coupling means, each of said openings () being aligned, at one cam position, to a further opening () for coupling means in the outer part (), the coupling means being configured and arranged so that, in a coupled state, each coupling means extends beyond the parting gap () on one coupling side () while simultaneously extending in the opening () of the outer and the inner part () which in an uncoupled position of the coupling means (), an axial idle stroke of the coupling means () on the one coupling side () till coupling is achieved is large and the axial idle stroke of the coupling means () on the further coupling side () till coupling is achieved is small. In this way, a switchable cam follower () or a switchable support element is crated in which the manufacturing costs, the complexity and also the risk of faulty couplings are drastically reduced.

Switched cam follower or switched support element of a valve gear of an internal combustion engine

The invention proposes a tappet () in a valve train of an internal combustion engine having a bottom camshaft for acting on a tappet push rod, said tappet being arranged with a housing () for axial displacement, but secured against rotation, in a guide bore () of the internal combustion engine () or of a component connected to the internal combustion engine, said housing () comprising on one front end (), two cheek-like extensions () that are situated diametrically opposite each other and are connected by an axle () on which a rotary roller () extends for making direct contact with a cam, said front end () comprising a transverse region () that connects the extensions () axially inside and has a cylindrical shape in a length direction of the roller (), and said guide bore () being intersected by two passages () for routing hydraulic medium to the tappet (), wherein a radius center point (M) of the transverse region () of the one front end () is situated with a lateral offset to a longitudinal axis of the tappet (), so that one side () of a periphery of the housing () between the extensions () is distinctly longer than an opposite side (), and the two passages () are led to the housing () at least approximately on the longer one side () of the periphery.

Tappet in a valve train of an internal combustion engine

A device for controlling cylinder disconnection in internal combustion engines, with a control device which permits in one of its two switching states an actuation of the valve concerned, with transmission devices which, in dependence on the switching state of the control device, transmit the cam stroke to the valve, and with a control unit acting on the control device. This provides a high switch over reliability with only small requirements for the changeover technology used. For this, the device has a data memory for the detection of the time course of the movement behavior of the gas exchange valves of cylinders of the internal combustion engine, and a data processing unit which provides a combination of gas exchange valves into valve groups with regard to a common activation or deactivation.

Device for controlling cylinder disconnection in an internal combustion engine

An internal combustion engine having a valve train that includes a switchable cam follower is provided. The cam follower () has a generally cylindrical shape and can move longitudinally in a receptacle () of the engine (), and is acted upon at one axial end by a cam () of a camshaft and at the other axial end indirectly or directly by a gas exchange valve of the valve train. A main oil gallery () is arranged in the internal combustion engine () for introducing hydraulic medium to a valve lash adjustment element arranged in the cam follower (). A switchable oil channel () is arranged in the internal combustion engine () for introducing hydraulic medium into a region of a switch element arranged in the cam follower (), wherein, the outer surface of the cam follower () has a helical groove (), through which at a peripheral point of the cam follower () the switchable oil channel () is connected hydraulically to the region of the switch element which opens at another peripheral point of the cam follower ().

Internal combustion engine with switchable cam follower

A hydraulic system ( ) for a switchable valve drive element ( ) of an internal combustion engine ( ) is provided and includes a throttled connection ( ) created from a second channel ( ), used to actuate a hydraulic play-compensation element ( ) using hydraulic fluid, directly to an external radial side ( ) of a coupling element ( ). The coupling element ( ) is supplied by a first channel ( ) with the switching hydraulic pressure. These measures make it possible to keep the first channel ( ) as free as possible of undesired air.

Hydraulic system for an internal combustion engine

In a valve drive for an internal combustion engine, an elongated securing device or anti-rotation bridge referred to as a mounting aid has receptacle spaces, arranged at intervals one behind the other, for receiving respective valve tappets. Each valve tappet can be displaced longitudinally in its receptacle space. The tappet is secured against rotation by two parallel planar keying faces formed on its outer surface which bear against corresponding inner surfaces in a receptacle space of the mounting aid. The mounting aid has receptacle spaces with a relatively small interval dimension between the two inner surfaces for bearing against the keying faces of standard roller tappets and has receptacle spaces with a relatively large interval dimension between the two inner surfaces for bearing against the keying faces of switchable roller tappets.

Valve drive for an internal combustion engine

What is proposed is a switchable tappet ( ) for the direct transmission of a cam lift to a tappet push rod. The tappet ( ) comprises a hydraulic clearance compensation element ( ) and has an excellent hydraulic rigidity compared to the prior art. This is achieved by a leak gap positioned radially very far outwards. This leak gap is situated directly between a housing ( ) and a pressure piston ( ) which, in its turn, encloses an inner element ( ) that acts on a tappet push rod.

Switchable tappet for the direct transmission of a cam lift to a tappet push rod

The invention proposes a switchable tappet ( ) for the direct transmission of a cam lift to a tappet push rod. A coiled compression spring ( ), used as a lost motion spring, for loading the inner element ( ) is shifted axially out of a housing ( ). For this purpose, the inner element ( ) comprises an extension ( ) that projects out of the housing ( ) and is surrounded by the coiled compression spring ( ). This measure contributes to minimizing the total mass of the switchable tappet ( ) because the overall length of the housing ( ) is shortened.

A switchable tappet for directly transmitting a cam lift onto a tappet push rod, includes a housing having a push rod distal end which is formed with a ramp surface for contact by a cam. An inner element is placed in a recess of thehousing and has a push rod proximal end formed with an abutment for the push rod. Secured to the push rod proximal end of the inner element is an attachment to extend the inner element beyond the recess of the housing, wherein the attachment has a housing-distal end formed with a shoulder. A helical compression spring extends between the shoulder of the attachment and a rim of the housing for urging the inner element in a direction of the push rod, and conically expands, at least partly, in the direction of the push rod and is wrapped around the attachment of complementary conical configuration.

Switchable tappet for directly transmitting a cam lift onto a tappet push rod

A cam follower (,) designed to be switchable between different lifts for at least one gas-exchange valve and includes two adjacent sections (,) which can be coupled together via a coupling element (,). The coupling element (,) cooperates with a shutoff slide (,). It is a special feature of the shut-off slide (,) that it is produced as a mechanically closable and openable piston for an inlet (,) in a pressure chamber (,) in front of the coupling means (,), the piston, however, being maintainable hydraulically in its open position via high switching pressure. At the same time, the shutoff slide (,) is completely incorporated in the cam follower (,) and does not extend beyond it. As a result, undesired fluctuations in the pressure of the hydraulic fluid can no longer act on the coupling means (,) during the base circle of the cams acting on the cam follower (,) and an intended turned-off state. At the same time, displacement of these coupling means (,) in their coupling direction is only possible if a sufficiently high pressure of the hydraulic fluid is available for such movement. Otherwise, the shutoff means (,), via the force of a pressing means (,), will close the inlet (,) for hydraulic fluid.

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Strullendorf, Germany

Henning Karbstein