(1) Classification according to the characteristics of hydraulic end According to the working organization can be divided into piston pump, piston pump and diaphragm pump; According to the characteristics of action can be divided into single-action pump, double acting pump and ink pump; Cylinder pumps, double cylinder pumps and multi-cylinder pumps. (2) According to the characteristics of power end can be divided into crank connecting rod mechanism, straight shaft eccentric wheel mechanism. (3) According to the driving characteristics can be divided into electric reciprocating pump, steam reciprocating pump and hand pump. (4) according to discharge pressure Pd size can be divided into low pressure pump (Xi d≤4MPa), medium pressure pump (4MPa (5) according to piston (or plunger) reciprocating times per minute can be divided into low- min), medium speed pump (80