Abstract: A lost motion engine valve actuation system and method of actuating an engine valve are disclosed. The system may comprise a valve train element, a pivoting lever, a control piston, and a hydraulic circuit. The pivoting lever may include a first end for contacting the control piston, a second end for transmitting motion to a valve stem and a means for contacting a valve train element. The amount of lost motion provided by the system may be selected by varying the position of the control piston relative to the pivoting lever. Variation of the control piston position may be carried out by placing the control piston in hydraulic communication with a control trigger valve and one or more accumulators. Actuation of the trigger valve releases hydraulic fluid allowing for adjustment of the control piston position. Means for limiting valve seating velocity, filling the hydraulic circuit upon engine start up, and mechanically locking the control piston/lever for a fixed level of valve actuation are also disclosed.

Abstract: A rocker arm assembly for an engine is disclosed. The rocker arm assembly comprises a rocker shaft having a first side and a second side and a rocker arm pivotably disposed on the rocker shaft. The rocker arm comprises a first portion disposed on the first side of the rocker shaft for receiving a force in a first direction from a brake actuator. The rocker arm further comprises a second portion disposed on the second side of the rocker shaft for engaging a valve in a second direction opposite the first direction. When the braking mode is desired, the brake actuator forces the first portion of the rocker arm in a first direction causing the rocker arm to transfer motion from the brake actuator to the exhaust valve or valves, thereby allowing exhaust to exit the combustion chamber.

Abstract: A valve operating system in an internal combustion engine includes an associative-operation switchover means capable of switching over the associative operation of a pair of rocker arms disposed adjacent each other and the releasing of the associative-operation. The associative-operation switchover means is provided between a plurality of rocker arms including the rocker arms disposed adjacent each other. In such valve operating system, through-bores are coaxially provided in support walls of the rocker arm, and opposite ends of a roller shaft are fitted and fixed in the through-bores. A spring-receiving member is mounted to the roller shaft for receiving a return spring. Thus, when the roller shaft with the return spring of the associative-operation switchover means accommodated therein is mounted to the rocker arm, it is possible to facilitate the processing and to reduce the size and weight of the rocker arm.

Abstract: In a valve operating system in an internal combustion engine, a swinging support section provided at a base end of a rocker arm is swingably carried on a rocker shaft, and tappet screws are threadedly fitted in a plurality of boss portions formed at a tip end of the rocker arm and arranged in a direction parallel to an axis of the rocker shaft, so that they can be individually put into abutment against upper ends of a plurality of engine valves. Cam abutments are provided on the rocker arm in an intermediate portion between the swinging support section and the boss portions to come into contact with a valve operating cam. The boss portions are interconnected by a connection wall having a plurality of wall portions which intersect each other in a plane perpendicular to the axis of the rocker shaft. Thus, the rigidity of the tip end of the rocker arm is enhanced sufficiently.

Abstract: In a valve operating system in an internal combustion engine, a rocker arm has a plurality of valve abutments provided thereon and capable of being individually put into abutment against upper ends of a plurality of engine valves cam abutments, and also has cam abutments provided thereon to come into contact with a valve operating cam. Wall-removed portions are formed in the rocker arm at locations corresponding to the cam abutments and open at opposite sides of the rocker arm. Thus, it is possible to provide a reduction in weight of the rocker arm.

Abstract: In a valve operating system in an internal combustion engine, a swinging support section provided at a base end of a rocker arm is swingably carried on a rocker shaft mounted in a cylinder head. A plurality of valve abutments are provided at a tip end of the rocker arm and capable of being individually put into abutment against upper ends of a plurality of engine valves, and a cam abutment is provided on the rocker arm in an intermediate portion between the swinging support section and each of the valve abutments to come into contact with a valve operating cam. The swinging support section comprises a thinner cylindrical portion surrounding the rocker shaft, and thicker cylindrical portions which are formed at a thickness larger than that of the thinner cylindrical portion into a cylindrical shape to surround the rocker shaft and which are integrally and continuously provided at axially opposite ends of the thinner cylindrical portion, respectively.

Abstract: An overhead cam engine with a drive train including a crankshaft, connecting rod, and piston assembly for reciprocating the piston within the cylinder bore of a cylinder block. A cam ring rotates on the same axis as that along which the piston reciprocates, and has lobes on its upper surface for periodically actuating a pair of rocker arms which open and close intake and exhaust valves located within the cylinder head. The cam ring is driven at half speed by the crankshaft through a gear train arrangement including a timing shaft disposed on an axis parallel to the piston axis with gears at both ends for connecting the crankshaft with the cam ring.

Abstract: In a valve mechanism of an internal combustion engine having a cylinder with a pair of air-intake valves, the number of operation modes of the air-intake valves in accordance with engine operation region is increased to improve combustion nature in a combustion chamber and engine output and to miniaturize the valve mechanism. The valve mechanism comprises first and second drive rocker arms operatively connected with the respective air-intake valves, first, second and third free rocker arms coming into contact with first, second and third operation cams having profiles for making the air-intake valve perform opening-closing motion.

Abstract: An internal combustion engine includes a housing; a camshaft rotatably carried by the housing and having a plurality of cams; a rocker arm shaft rotatably carried by the housing and rotatably driven by the camshaft; and a plurality of rocker arms rotatably carried by the rocker arm shaft, with each rocker arm being associated with a respective cam. The rocker arm shaft and camshaft each include a gear these two gears enmeshing with each other. Rotating the camshaft in turn rotatably drives the rocker arm shaft within the rocker arms.

Abstract: A low friction, wear-resistant pin for a cam follower roller useful in the injector and valve trains of internal combustion engines, particularly diesel engines, to enhance cam durability and life is provided. The material selected for the pin, which is selected for its wear resistance, its corrosion resistance, its low friction, and its ability to embed hard debris and other oil contaminants without scuffing, has been demonstrated to improve cam life dramatically. A preferred roller pin material that achieves this objective is a copper-based alloy, most preferably a leaded manganese silicon bronze.