Abstract: A switch element (1) is proposed for valve shut-off, fabricated as cam follower for a plunger rod valve drive of an internal combustion engine, having an outer part (2) and an inner element (4) axially movable in its bore (3) and with rotational security (15) relative to the guided inner element (4). The outer part (2), inside the bore (3), has an annular groove (6), and the inner element (4) has a radial bore (7) with two diametrically opposed pistons (8), which to couple the elements (2, 4) in their axially remote relative position achieved by a lost-motion spring (5) are displaceable towards the annular groove (6). On their cam-side under side, emanating from their radially outward, bulbous face, the pistons (8) segmentwise comprise a plane transverse surface as contact area for a facing under side (27) of the annular groove (6). The latter is intersected by two diametrically opposed oil ports (11) running offset 90° from the pistons (8) in circumferential direction.

Abstract: The hydraulic play compensation device, having an outer cylinder part which is closed on one side by a base and in which a piston element which lies on its inside is guided so as to be longitudinally displaceable, with a guide gap, having an oil pressure space having an oil inlet which supplies the oil supply space, and having a connecting duct controlled by a nonreturn valve between the oil supply space and the oil pressure space. For optimized removal of air which is introduced via the oil inlet, it is proposed that a ventilation path which connects the oil supply space and the guide gap is formed in the piston element downstream of the oil inlet and upstream of the connecting duct.

Abstract: A guide rail (1, 22) for valve tappets (2) of an internal combustion engine is provided. The guide rail (1, 22) has receptacle spaces (4), which are each used for receiving one of the valve tappets (2) and in which there are flattened sections (6) interacting in a positive-fit connection with key surfaces (7) of the valve tappets (2), such that each of the valve tappets (2) is protected from rotating about its longitudinal axis, with the flattened sections (6) permitting alignment of the valve tappet (2) parallel to the flattened sections (6). Here, the guide rail (1, 22) is formed as a metal carrier (3, 25) and rotational protection elements (8, 9, 23), which are fixed on this carrier, have the flattened sections (6) which also permit alignment of the valve tappet (2) orthogonal to the flattened sections (6), in that each flattened section (6) belonging to one of the receptacle spaces (4) can be displaced relative to the metal carrier (3, 25).

Abstract: The invention relates to a hydraulic tappet clearance compensation device (1) for a valve gear of an internal combustion engine, the high pressure chamber (8) of which device can be rapidly and easily vented. For this purpose an annular collar (11) has radial openings (16) distributed over the circumference of its pressure piston (5). These allow air bubbles, which accumulate between an outer shell of the annular collar (11) and a bore (3) of a housing (2), to escape to a bore (9) for a non-return valve (10) and hence directly into the open. There is therefore no need for venting via a leakage gap (13) between the pressure piston (5) and the housing (2), which has hitherto yielded only unsatisfactory results.

Abstract: 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.

Abstract: A reverse spring hydraulic valve-lash-adjusting element for the valve train of an internal combustion engine having a plunger (1), in the plunger head (2) of which a control valve (5) is arranged, this control valve (5) controlling a central axial bore (6) which connects a low-pressure space (4), arranged above the plunger head (2), to a high-pressure space (3) arranged below the plunger head (2), the control valve (5) having a valve-closing body (7) which is loaded in the opening direction by a valve-body spring (17) and as a result passes from a cylinder-ring-shaped sealing surface (8) arranged on the plunger head (2) to a travel-limit surface (9) of a center piece (24), whereas the closing of the control valve (5) is effected by displacement of oil from the high-pressure space (3) into the low-pressure space (4) wherein the valve-closing body (7) reaches the sealing surface (8) on a linear path without lateral movement or rotation of said valve-closing body (7) by virtue of the fact that a circular-cylindr

Abstract: The invention relates to a hydraulic tappet clearance compensation device (1) for a valve gear of an internal combustion engine, the high pressure chamber (8) of which device can be rapidly and easily vented. For this purpose an annular collar (11) has radial openings (16) distributed over the circumference of its pressure piston (5). These allow air bubbles, which accumulate between an outer shell of the annular collar (11) and a bore (3) of a housing (2), to escape to a bore (9) for a non-return valve (10) and hence directly into the open. There is therefore no need for venting via a leakage gap (13) between the pressure piston (5) and the housing (2), which has hitherto yielded only unsatisfactory results.

Abstract: A switchable valve-drive component (1) for variable transmission of a stroke generated by one or more cam projections to a gas-exchange valve of an internal combustion engine is provided. The valve-drive component (1) has transmission elements (3, 4), which can be connected with a positive fit by coupling elements (8) in the transmission direction, in which force transmission surface sections (16) of the coupling elements (8) can be clamped between force transmission surface sections (20) of the transmission elements (3, 4). Here, at least one of the force transmission surface sections (16, 20) should be provided with a wear protection layer (23). This layer comprises at least one metal-free amorphous hydrocarbon layer with sp2-hybridized and sp3-hybridized carbon.

Abstract: A switch element (1) is proposed for valve shut-off, fabricated as cam follower for a plunger rod valve drive of an internal combustion engine, having an outer part (2) and an inner element (4) axially movable in its bore (3) and with rotational security (15) relative to the guided inner element (4). The outer part (2), inside the bore (3), has an annular groove (6), and the inner element (4) has a radial bore (7) with two diametrically opposed pistons (8), which to couple the elements (2, 4) in their axially remote relative position achieved by a lost-motion spring (5) are displaceable towards the annular groove (6). On their cam-side under side, emanating from their radially outward, bulbous face, the pistons (8) segmentwise comprise a plane transverse surface as contact area for a facing under side (27) of the annular groove (6). The latter is intersected by two diametrically opposed oil ports (11) running offset 90° from the pistons (8) in circumferential direction.

Abstract: A hydraulic valve play compensation element for an internal combustion engine is provided as a reverse-spring/free-ball element, with a cylindrical housing, a cylindrical piston (21) guided therein with sealing play and a control valve (20), which is arranged between a low-pressure chamber (22) of the piston (21) and a high-pressure chamber (24) of the housing, on a piston head (25) of the piston and which has a closing body (27), which can contact a valve seat (26) surrounding an axial bore hole (23) of the piston head (25) when carrying out a stroke (28) in the closing direction against the force of a control-valve spring (34) and which can contact a contact surface (29) of a valve cap (30) surrounding the closing body (27) when carrying out a stroke in the opening direction.

Abstract: The invention proposes a switching element (1) for a valve train of an internal combustion engine, particularly for valve deactivation, with a simple-to-implement measure for adjusting the coupling lash of its coupling means (8) in a receptacle (6) using two retaining rings (19, 20), one of which is stocked in a variety of thicknesses.

Abstract: The invention concerns a mounting and anti-rotation device (mounting aid) (1) for roller tappets of a valve train of an internal combustion engine in which gas exchange valves are activated by roller tappets. The roller tappets comprising a substantially cylindrical tappet body are retained in receptions (7, 8) of the mounting aid (1) that is made of plastic. With the help of opposing parallel anti-rotation surfaces that are arranged symmetrically to the longitudinal axis of the roller tappet and are disposed on the end of the tappet body that is oriented away from a roller, the roller tappets are guided secured against rotation in the mounting aid during the operation of the internal combustion engine. This is achieved by the fact that the inner profile of the receptions (7, 8) is matched to the outer profile of the roller tappets.

Abstract: The invention concerns a mounting and anti-rotation device (mounting aid) (1) for roller tappets of a valve train of an internal combustion engine in which gas exchange valves are activated by roller tappets. The roller tappets comprising a substantially cylindrical tappet body are retained in receptions (7, 8) of the mounting aid (1) that is made of plastic. With the help of opposing parallel anti-rotation surfaces that are arranged symmetrically to the longitudinal axis of the roller tappet and are disposed on the end of the tappet body that is oriented away from a roller, the roller tappets are guided secured against rotation in the mounting aid during the operation of the internal combustion engine. This is achieved by the fact that the inner profile of the receptions (7, 8) is matched to the outer profile of the roller tappets.

Abstract: Valve train with hydraulic lash adjustment in the entire timing train, in which oil is delivered from the oil supply space of the hydraulic valve-lash adjuster (HLA) to the valve rocker arm via a hollow push rod, a choke limiting the oil discharge, the choke being designed in such a way that it seals off the push rod bore at the top when the oil pressure drops, that is to say when the engine is shut off, so that the oil is retained in the push rod bore (12) until—after the engine is started—the choke body (15, 22) opens up the discharge opening again.

Abstract: The invention proposes a coupling mechanism (1) for relatively movable elements (2, 3) of a switchable cam follower (4) of a valve train of an internal combustion engine, a high lift being obtainable upon coupling of said elements (2, 3) and a lift smaller than the high lift being obtainable upon uncoupling of said elements (2, 3), a first one (2) of said elements comprising a guide bore (5) for at least one coupling piston (6) which, for achieving coupling, can be displaced partly beyond a parting surface (7) between said elements (2, 3) into an aligned reception (8) of a second one (3) of said elements, wherein upon cam lift and coupling of said elements (2, 3), a contact zone (9) between the piston (6) and the reception (8) is clearly spaced from an edge section (10) of the reception (8) on the parting surface (7). This can be implemented in practice, for instance, through a special “backwards” oriented flattened portion (14) on the piston (6). Material loading on the edge section (10) is thus avoided.

Abstract: What is proposed is a hydraulic lash adjuster (1), for example for a valve train of an internal combustion engine. The lash adjuster (1) comprises a hollow cylindrical housing (2) that is inter-inserted with an axially relatively displaceable pressure piston (3). A high pressure chamber (6) for hydraulic medium extends between opposing front ends (4, 5) of the pressure piston (3) and the housing (2). The high pressure chamber (6) can be supplied, via a one-way valve (8) arranged on the front end (4) and opening towards the high pressure chamber (6) with hydraulic medium out of a reservoir (9). A leak gap (12) for the hydraulic medium is formed between an outer peripheral surface (10) of the pressure piston (3) and a bore (11) of the housing (2). In its portion adjoining the front end (5) of the housing (2), the bore (11) of the housing (2) merges into an annular enlargement (15).

Abstract: 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.

Abstract: A switch element (1) is proposed for valve shut-off, fabricated as cam follower for a plunger rod valve drive of an internal combustion engine, having an outer part (2) and an inner element (4) axially movable in its bore (3) and with rotational security (15) relative to the guided inner element (4). The outer part (2), inside the bore (3), has an annular groove (6), and the inner element (4) has a radial bore (7) with two diametrically opposed pistons (8), which to couple the elements (2, 4) in their axially remote relative position achieved by a lost-motion spring (5) are displaceable towards the annular groove (6). On their cam-side under side, emanating from their radially outward, bulbous face, the pistons (8) segmentwise comprise a plane transverse surface as contact area for a facing under side (27) of the annular groove (6). The latter is intersected by two diametrically opposed oil ports (11) running offset 90° from the pistons (8) in circumferential direction.

Abstract: 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.

Abstract: Cam for actuating a valve mechanism of an internal combustion engine, having a cam base circle (33), a main cam region (32) and a pre-cam region (31), which is formed between the cam base circle (33) and main cam region and directly precedes a rising section (32a) of the main cam region (32), wherein the pre-cam region (31) has a profile which effects an increase in the cam lift speed followed by a decrease in the cam lift speed followed by a further increase in the cam lift speed.