Abstract:
The invention proposes a switchable component (1) for a valve train of an internal combustion engine, said component (1) comprising a housing (2) in whose bore (3) an axially displaceable inner element (4) comprising coupling elements (5) is received, said coupling elements (5), for effecting coupling, being able to be brought partially into engagement with an entraining surface (6) of the housing (2), the inner element (4) being biased in outward direction from the housing (2) by a lost motion spring (7), and an (outer) anti-rotation device (11) extending from an outer casing (10) of the housing (2) projects beyond a surrounding structure (12a), the outer anti-rotation device (11) is configured as a C-shaped, thin-walled ring (13) comprising a slit (12), said ring (13) extends after the manner of a clip in an annular groove (14) in the outer casing (10) of the housing (2) parallel to a transversal plane of the component (1) and, for effecting outer anti-rotation, said ring (13) projects with a sickle-like portion (15) of its outer peripheral surface (16) beyond the outer casing (10) of the housing (2).
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. In a region of the axial bore hole (23) for the closing body (27) there is a narrow guidance surface (32) with gaps, which enable a volume flow of hydraulic medium between the high-pressure chamber (24) and the low-pressure chamber (22).
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:
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). According to the invention, the front end (4) of the pressure piston (3) comprises in its transition region to the outer peripheral surface (10), a chamfer (16) whose height (HF) is equal to or larger than a height (HR) of the annular enlargement (15). In this way, it is effectively prevented that undesired particles situated in the high pressure chamber (6) get deposited on the outer peripheral surface (10) of the pressure piston (3) in the sunk state thereof, and penetrate into the leak gap (12) during the subsequent adjusting operation with the danger of a clamping of the pressure piston (3).
Abstract:
Deactivation apparatus for selected cylinders of an engine include switching hydraulic lash adjusters or valve lifters forming part of a valve train for actuating engine valves of the selected cylinders and operable to actuate or release their respective valves in response to an oil pressure signal. A gallery carrying the lash adjusters includes oil passages fed by an engine pressure oil supply through a control valve to supply oil to switching portions of the lash adjusters. The control valve is operative to close or open communication of the oil supply with the lash adjusters and to relieve oil pressure in the passages when communication with the pressure oil supply is closed. Various bypass alternatives between the pressure oil supply and the oil passages carry oil to portions of the oil passages to purge air from the passages when the three-way valve exhaust port is open.
Abstract:
In a valve train of an internal combustion engine, which valve train comprises an elongate anti-rotation bridge (6) comprising receptions spaced behind one another for receiving valve tappets configured as roller tappets (4), one of which tappets is arranged in each reception and is directed with a tappet roller (3) toward a cam (2) of a camshaft (1), the roller tappet (4) of the invention comprises on an outer peripheral surface, raised tappet contours (10, 11) that engage into retention grooves of the bridge (6) within the reception.
Abstract:
A roller cam follower has a transverse bearing shaft that is restrained against substantial lateral motion in a follower body supporting the shaft which rotatably carries a cam follower roller. The follower roller is rotatably mounted in a recess between opposite sides of the body on the transverse bearing shaft, which is supported in shaft bores through the sides of the body. One or more retainers are pressed onto the shaft within the recess and are operatively engageable with the sides of the body to limit axial motion of the shaft in said shaft bores. Various embodiments of retainers are disclosed as are applications to various types of roller cam followers, such as valve lifters, finger followers and rocker arms.
Abstract:
A tappet comprises a foot having a convex cam contact surface and an axially extending hub, a tappet body having a lower body portion with a lower axial bore formed therein to receive the axially extended hub of the foot, and a bearing assembly positioned between the foot and the lower portion of the tappet body. The cam contact surface operates in a frictional relationship with a cam lobe of a rotating cam. The frictional relationship between the cam lobe and the cam contact surface of the foot induces the foot to rotate about the center line of the tappet. The bearing assembly operates to reduce friction as the foot independently rotates axially about a center line of the tappet body.
Abstract:
A tappet comprises a foot having a convex cam contact surface and an axially extending hub, a tappet body having a lower body portion with a lower axial bore formed therein to receive the axially extended hub of the foot, and a bearing assembly positioned between the foot and the lower portion of the tappet body. The cam contact surface operates in a frictional relationship with a cam lobe of a rotating cam. The frictional relationship between the cam lobe and the cam contact surface of the foot induces the foot to rotate about the center line of the tappet. The bearing assembly operates to reduce friction as the foot independently rotates axially about a center line of the tappet body.
Abstract:
A damping mechanism for a lost motion hydraulic actuator utilizes a thin edge orifice in cooperation with a communication passageway between the upper and lower chambers controls the damping of the upper piston on closure. The upper piston is operatively connected to the engine valve of an internal combustion engine. A communication port from the upper chamber to the communication passageway is closed off as the upper piston returns to its normal position forcing the flow of the hydraulic fluid through the thin edge orifice. In this manner the viscosity of the hydraulic fluid does not control the damping of the actuator and the noise factor is substantially reduced.