An opposed-piston engine optionally contains an ignition system that is at least partially contained within the combustion chamber to enhance the combustion efficiency of a fuel-air mixture within the combustion system. More specifically, the ignition system contains at least one spark plug having an elongated center electrical delivery electrode, and, an elongated ground electrode. Accordingly, the elongated electrodes extend from an area adjacent to the inner periphery of the cylinder to a radially central area within the combustion chamber. Yet further, a cooling jacket is incorporated to provide cooling of the spark plug.

A valve timing adjustment device includes: a first rotatable body that is rotated about a rotational axis synchronously with one of a drive shaft and a driven shaft of an engine; and a second rotatable body that is rotated about the rotational axis synchronously with the other one of the drive shaft and the driven shaft. The first rotatable body includes: a fastening portion, a slide portion and a bearing portion. The fastening portion is fastened to the one of the drive shaft and the driven shaft. The bearing portion includes an outer peripheral surface that is opposed to an inner peripheral surface of the second rotatable body, and the bearing portion rotatably supports the second rotatable body. The fastening portion projects on one axial side of the slide portion and the bearing portion in an axial direction toward the one of the drive shaft and the driven shaft.

Presented are variable compression ratio and independent compression and expansion engines, methods for making/operating such engines, and vehicles equipped with such engines. An engine assembly includes an engine block with a cylinder bore defining a combustion chamber, and a piston movable within the cylinder bore. A valve assembly, which is fluidly coupled to the combustion chamber, selectively introduces/evacuates fluid from the combustion chamber. A crankshaft is supported by the engine block and rotatable on a first axis. A multipoint linkage, which drivingly engages the piston to the crankshaft, rotates on a second axis offset from the first axis. A control shaft is supported by the engine block and rotates on a third axis offset from the first and second axes. The control shaft operable to selectively rotate the multipoint linkage on the second axis, and is operable to selectively unseat the valve assembly.

A four-stroke opposed piston engine contains a drive train containing two outer crank shaft gears, and two inner synchro gears, wherein the inner synchro gears are twice the diameter of the outer crank shaft gears. Additionally, novel piston faces are presented that when fixed on opposed pistons, create annular cavities that form advantageous combustion chambers when the pistons are at top dead center.

The present disclosure provides a remote mount for an idler gear assembly, comprising: a gear mounting plate including a plurality of bores configured to receive a corresponding plurality of fasteners to mount a gear assembly to the gear mounting plate; and an attachment bracket including a plurality of mounting openings configured to receive a corresponding plurality of bolts to mount the remote mount to a cylinder head. The gear mounting plate supports the gear assembly such that a gear of the gear assembly rotates about an axis that is parallel to an axis of a crankshaft of an engine and the attachment bracket mounts to an upper surface of the cylinder head.

A hydraulic type scissors gear removes factors that generate a backlash due to reduction of tension of existing springs by generating a relative motion between gears using oil pressure. The hydraulic type scissors gear includes: a first gear having an operation chamber and supplied with oil in the operation chamber; a second gear coaxially disposed on a side of the first gear to be rotate relative to the first gear; and a piston configured to rotate the second gear by applying force that pushes the second gear in a rotational direction opposite to a rotational direction of the first gear by being moved in the operation chamber by oil pressure supplied to the operation chamber.

An opposed-piston engine includes an engine block, at least two intake valves, and at least two exhaust valves. The engine block includes a first center section and a second center section. The first center section defines a first cylinder half bore having a first longitudinal axis and a first open end. The second center section defines a second cylinder half bore having a second longitudinal axis and a second open end. The second longitudinal axis is offset from the first longitudinal axis. The first and second open ends overlap to form and opening therebetween that places the first and second cylinder half bores in fluid communication with one another to form a single cylinder. The intake valves are arranged at the first open end of the first cylinder half bore. The exhaust valves are arranged at the second open end of the second cylinder half bore.

An opposed-piston internal combustion engine is configured so that one cylinder is provided with two pistons and these pistons reciprocate symmetrically with each other. The engine comprises: an expanded chamber formed at part of a wall of the cylinder positioned between the two pistons when a volume between the two pistons is the minimum and extending in a radial direction of the cylinder; an intake passage communicated with the expanded chamber; an exhaust passage communicated with the expanded chamber; an intake valve opening and closing the intake passage with respect to the expanded chamber; an exhaust valve opening and closing the exhaust passage with respect to the expanded chamber, and crankshafts respectively connected to the pistons. The expanded chamber formed so as to stick out from a wall surface of the cylinder in the same direction as axes of rotation of the crankshafts.

Systems, devices, and methods are disclosed for supporting one or more camshafts by the engine block in overhead arrangement relative to the cylinder heads and valve train.

An improved, lightweight gear drive having a rim gear mounted on a shaft, the shaft formed of one or more shaft segments, each of the shaft segments supporting a segregated arc. The segregated arcs forming a circumferential portion of a bearing surface of the shaft.