I.c. engine without an overall lubricating oil circuit; it has rolling bearings between piston and cylinder and separate lubrication of valve gear and crank

Each piston 5 has a number of linear rolling bearings 4 which roll along a line on the inner wall of the cylinder liner 6. The bearings 4 may require no lubrication or may have minimum-quantity or lifetime lubrication. The valve gear 2 may be electromagnetic or electrohydraulic, requiring no lubricant. Alternatively, the valve gear may have lifetime, grease or solid lubrication. The main crankshaft 9 bearing and the crankpin/connecting rod bearing 10 may have lifetime lubrication in encapsulated form or may have its own lubricant circuit, eg using diesel fuel as the lubricant. Alternatively, a ferrofluid lubricant may be used, held in place by permanent magnet rings. Engine auxiliaries have respective alterative lubricants or minimum-quantity lubricants. The engine does not need oil-changes, oil consumption is reduced and particle and HC exhaust emissions are reduced.