Abstract: A rocket engine has a combustion chamber, an injector, and an attachment between the combustion chamber and the injector. The attachment includes an annular metallic deposit joined to the chamber wall outer surface, and an annular transition ring structure. The transition ring structure has an annular step collar, and an annular adaptor ring brazed to the annular step collar. The adaptor ring is welded on one end to the injector and on the other end to the metallic deposit.

Abstract: A rocket engine includes a generally cylindrical annular combustion chamber, an injector attached to an injector end of the combustion chamber, a generally cylindrical annular step collar fitting within the combustion chamber at the injector end thereof, and an attachment of the combustion chamber, the injector, and the step collar. The maximum outer diameter of the step collar is from about 0.020 inches to about 0.024 inches smaller than the inner diameter of the combustion chamber, and has a length of from about 21 to about 31 percent of the length of the combustion chamber. The step collar is made of a material having a melting point greater than that of the combustion chamber. The attachment preferably includes a clip structure joining the combustion chamber and the step collar.

Abstract: A rocket engine is fabricated by a multistep brazing and welding technique. An annular step collar is fns brazed to a trnnsition joint. This first subassembly is second brazed to the combustion chamber. This second subassembly is third brezed to an annular adaptor to form a third subassembly. The succeeding brazing steps are performed at successively lower temperatures. The third subassembly is welded to an injector.