A self-resetting single-valve double-piston hydraulic drive device and method for an overhead cam engine is disclosed. A primary driving piston and a secondary driving piston are respectively provided on a rocker arm body and a valve bridge body. The secondary driving piston is connected to an exhaust valve. When the drive control valve opens, the primary driving piston and the secondary driving piston realize a hydraulic linkage, during a drive lift, the secondary driving piston opens the exhaust valve. At the beginning of the positive-power lift, the secondary driving piston is automatically reset. When the control valve is closed, during the drive lift of an integrated cam, the primary driving piston absorbs the drive lift of an integrated cam assembly, the rocker arm body and the bridge body do not move, and the drive lift of the integrated cam is not transmitted to the exhaust valve.

Methods and systems are provided for a valve system for actuating two cylinder valves in an engine. In one example, the valve system may include a single pump and a solenoid valve capable of non-concurrently actuating the two cylinder valves coupled to separate cylinders.

A rocker arm assembly including a rocker body having an upper wall arranged above a pivot axis, two ears extending from opposing sides of the upper wall and defining a pivot bore coaxial with the pivot axis, and a pad end wall and a socket end wall each extending from the upper wall and the ears. A pad having a convex pad surface is formed on the pad end wall for engaging a valve and a socket having a concave socket surface is formed on the socket end wall for engaging a pushrod. The rocker arm assembly further includes a trunnion body and a bearing, each disposed in the pivot bores and for facilitating pivoting movement between the rocker body and the trunnion body.

The present invention provides for Variable Valve Actuation comprising a cam, a valve suitable to displace between a closed position and an open condition caused by said cam, and further comprising a main rocker arm suitable to swing over a fulcrum, mechanically interacting with said valve, by means of a guide profile, and wherein said cam interacts with said main rocker arm causing said valve displacement as a consequence of said main rocker arm swinging. The target is to prevent a valve brake due to the guide profile and enable higher system stiffness. Accumulator less designs are feasible with this system.

A valve actuation system for an engine includes a rotatable camshaft, an injector actuation linkage, and a valve actuation linkage. The valve actuation linkage includes a valve lifter, a valve pushrod, and a rocker arm. At least one of a rocker arm center plane defined by the valve rocker arm or a lifter roller center plane defined by the valve lifter is spaced an offset distance from a pushrod axis, providing an increased contact width between an injector roller in the injector actuation linkage and one of a plurality of cam lobes of the camshaft. The valve lifter includes a fork defining a center plane spaced an offset distance from a center axis of the valve lifter. A rocker arm includes a screw bore offset relative to a rocker arm center plane.

A rocker arm has two side walls and two webs which run transversely with respect to the side wall. The webs connect the side walls to one another on end-side sections, wherein a valve stem support is configured on one of the webs, and a spherical cap is configured on the other web. A cam roller is arranged in a roller pocket which is delimited by the webs and the side walls. The cam roller is mounted rotatably on a roller axle which is fixed in the side walls. Projections are arranged within the roller pocket such that they are spaced apart from the respective web to guide the cam roller. The projections extend from the side walls in the direction of the cam roller to form guide surfaces which interact with end surfaces of the cam roller.

A rocker arm assembly including a rocker body having an upper wall arranged above a pivot axis, two ears extending from opposing sides of the upper wall and defining a pivot bore coaxial with the pivot axis, and a pad end wall and a socket end wall each extending from the upper wall and the ears. A pad having a convex pad surface is formed on the pad end wall for engaging a valve and a socket having a concave socket surface is formed on the socket end wall for engaging a pushrod. The rocker arm assembly further includes a trunnion body and a bearing, each disposed in the pivot bores and for facilitating pivoting movement between the rocker body and the trunnion body.

A switchable finger follower for a valve train of an internal combustion engine includes an outer and an inner lever, which at a first longitudinal end run pivotably relative to one another via respective bores on a common shaft. At this longitudinal end, the finger follower has a gas-exchange valve contact face on an underside. The outer lever has a pivot bearing on the underside at a further longitudinal end, and at least the inner lever has a cam running face on an upper side. The inner and outer levers are connectable to one another via at least one coupling slide, which spans a separation area between the levers. The outer and inner levers are braced relative to one another via a cam return spring, and the shaft is connected to the bore of the outer lever by an interference fit. To mount the inner lever relative to the shaft without radial play but in a rotatable fashion, the bore of the inner lever includes, in its semi-circular segment facing the upper side, a pointed arch composed of two circular arcs as contact means.

The invention relates to a variable valve train for switching an outlet valve of an internal combustion engine to an engine braking mode. The variable valve train has a camshaft with a first cam, which is designed as a normal operation cam, and a second cam, which is designed as an engine braking cam. A first rocking lever has a first stroke device which is designed for selectively making or breaking a first operative connection between the first cam and the outlet valve by means of the first rocking lever. A second rocking lever has a second stroke device which is designed for selectively making or breaking a second operative connection between the second cam and the outlet valve by means of the second rocking lever. A valve device selectively connects the first stroke device or the second stroke device to a fluid feed line.

A self-resetting single-valve double-piston hydraulic drive device and method for an overhead cam engine is disclosed. A primary driving piston and a secondary driving piston are respectively provided on a rocker arm body and a valve bridge body. The secondary driving piston is connected to an exhaust valve. When the drive control valve opens, the primary driving piston and the secondary driving piston realize a hydraulic linkage, during a drive lift, the secondary driving piston opens the exhaust valve. At the beginning of the positive-power lift, the secondary driving piston is automatically reset. When the control valve is closed, during the drive lift of an integrated cam, the primary driving piston absorbs the drive lift of an integrated cam assembly, the rocker arm body and the bridge body do not move, and the drive lift of the integrated cam is not transmitted to the exhaust valve.