Classification of hydraulic pumps that serve as the heart of hydraulic systems in manufacturing. Includes various pumps used in hydraulic drive systems for machine tools, press machines, injection molding machines, construction machinery, and other equipment. Primarily consists of positive displacement pumps such as gear pumps, vane pumps, and piston pumps that supply high-pressure, high-flow hydraulic fluid. Features diverse drive methods including motor-driven, engine-driven, and manual types, selected according to system pressure and flow requirements. Distinguished from hydraulic cylinders and motors, classified purely as equipment that generates hydraulic energy.