Reciprocating type IC engine - has combined cylinder and piston in form of bellows of special material

Each cylinder is constructed as a metallic bellows of a suitable alloy. One end is fixed and contains the inlet and exhaust valves and if appropriate a sparkling plug. The other end is free to move linearly and has a straight tubular end piece which is guided to ensure linear motion. This piece is attached to the small end of a connecting rod of a conventional crank mechanism. The working process takes place within the bellows which expands and contracts to vary the vol. inside it thus combining the functions of the cylinder and the piston. No lubrication is necessary within the combustion chamber and no seal is needed between piston and cylinder.