Cooling circuit for rotary piston internal combustion engines

Claim 1

A rotary piston internal combustion engine in which a peripheral envelope and lateral cheeks form a casing for the piston, said envelope having inner and outer surfaces and having at least one active part through which relatively high heat fluxes have to be removed, at least one passage for flow of a liquid coolant therethrough being arranged between Said inner and outer surfaces so as to traverse at least one said active part of the envelope, said passages having successive sections of predetermined cross-sectional areas in said active parts, said cross sections being predetermined from the heat flux characteristics of the coolant liquid, so that under normal operating conditions thermal exchange at any cooled point of the envelope takes place under conditions of convection and so that the temperature difference between the envelope and the liquid is smaller by a substantially constant value than the temperature difference corresponding to transition from said convection conditions to thermal exchange under substantially nuclear ebullition conditions, wherein said passage is arranged in the neighborhood of said inner surface, and comprised between two cylindrical surfaces, the first of which is substantially parallel to said inner surface, and the second of which surrounds the first at a distance depending on the cross section of the passage, said two cylindrical surfaces being connected together by ribs which are substantially parallel to the mean plane perpendicular to the generatrixes of said cylindrical surfaces, said ribs being disposed in staggered relation with respect to said plane, said cheeks limiting said passage laterally.