Abstract: A camshaft for the drive of an internal combustion engine has a hollow shaft carrying one or more cams or partial cams and an inner shaft disposed within the hollow shafts and rotatable relative to the hollow shaft. The inner shaft has one or more cams or partial cams disposed outside the hollow shaft and attached for rotation with the inner shaft through clearances in the hollow shaft. A camshaft driving arrangement includes a camshaft timing gear coupled with both shafts and a device responsive to a parameter characteristic of the operating conditions of the drive for adjusting the rotational position of either one or both of the inner and hollow shafts relative to the camshaft timing gear. The adjusting device includes an electric motor fixed on the timing gear and controlled by electrical signals.

Abstract: A camshaft for an internal combustion engine having a hollow shaft carrying one or more cams or partial cams for rotation therewith and an inner shaft disposed within the hollow shaft and rotatable relative to the hollow shaft. The inner shaft has one or more cams or partial cams disposed outside the hollow shaft attached for rotation with the inner shaft through clearances in the hollow shaft. A camshaft drive includes a means responsive to the parameter characteristic of engine operating conditions for adjusting the rotational position of at least one of the shafts relative to the drive. The adjustment mechanism includes a radially extending guide on the drive, and an adjustment cam having a cam surface thereon and mounted on the guide to be radially displaceable therealong. A means is provided responsive to the desired engine parameter for varying the radial displacement of the adjustment cam.

Abstract: This invention is an apparatus for partial balancing of the free inertia forces and inertia moments of a reciprocating piston-crankshaft engine which is comprised of a pair of eccentrically weighted balancing masses mounted on an axial end of the engine. The balancing masses are mounted on drive pulleys which can be driven in opposite directions by a toothed-belt with teeth on both sides which is connected to the crankshaft. The balancing masses are arranged so that their centrifugal force components extending parallel to the cylinder axes are added and the centrifugal force components extending perpendicular to the cylinder axes cancel each other out and the axes of rotation of the pulleys are offset relative to each other in the direction of the cylinder axes.