Opposed piston combustion engine

An internal combustion engine comprising at least one cylinder module, said cylinder module comprising:

• a shaft having a first multilobate cam axially fixed to said shaft and an adjacent second multilobate cam differentially geared to said first multilobate cam for axial counter rotation about said shaft;
• two pairs of cylinders associated with said multilobate cams, each pair of cylinders driving a respective one of the multilobate cams, each pair of cylinders having an axis, the cylinder of each pair being diametrically opposed with respect to said shaft with said multilobate cams interposed therebetween;
• and
• a piston in each said cylinder, which pistons of a pair of cylinders are rigidly interconnected;
• wherein:
• said multilobate cams each comprise 3+n lobes where n is zero or an even-numbered integer;
• and, the axes of the pairs of cylinders are at an angle to each other of half of the number obtained by dividing 360° by the number of lobes on a cam;
• and wherein, reciprocating motion of said pistons in said cylinders imparts rotary motion to said shaft via contact between said pistons and the camming surfaces of said multilobate cams.