Machines in the nature of pumps and motors for transforming mechanical energy into hydrostatical energy or vice versa; hydraulic aggregates, namely, power packs for industrial and mobile applications; pumps, namely, [ electric, electromagnetic, pneumatic or ] hydraulic pumps, preferably fluid pumps, particularly machine-powered fluid pumps, [ water-hydraulic pumps, ] and parts thereof; [ piston pumps, namely, radial or axial piston pumps; ] gear pumps, namely, internal-gear pumps [ or externa...