7 Power transmissions for machines and replacement parts therefor; machine couplings and transmission components, except for land vehicles and parts therefor; couplings for transmission shafts being parts of machines, except land vehicles; couplings for drive shafts being parts of machines, except land vehicles; transmission shafts, other than for land vehicles and parts therefor; drive shafts for machines, except land vehicles, and parts therefor; bearings for transmission shafts being parts of machines; bearings for drive shafts being parts of machines, except land vehicles; universal joints for transmission shafts being parts of machines, except land vehicles; universal joints for drive shafts being parts of machines, except land vehicles; cardan cross links and cross link assemblies comprised of universal joints for transmission shafts, being parts of machines, except land vehicles; cardan cross links and cross link assemblies comprised of universal joints for drive shafts, being parts of machines, except land vehicles