SCY14-1B manually variable axial piston pump, as shown in Figure 2. The principle to turn the hand wheel so that the piston moves up and down, driven by variable head tilt angle changes, changing the piston stroke length, the purpose of the variable. Case of such a variable type is only suitable for non-frequent variable, and the remote control is not required. The use of high-pressure piston pump pressure should generally be between 10MPa ~ 100MPa. It belongs to the positive displacement pump, by means of a periodic variation of the volume of the working chamber to achieve the purpose of conveying the liquid; mechanical energy of the prime mover via a pump directly converted to the conveying pressure of the liquid; capacity of the pump depends on the volume of the working chamber only change value the number of changes within a unit time, in theory, with the discharge pressure independent. The reciprocating pump is by means of the reciprocating movement of the piston in the working chamber of the hydraulic cylinder (or by a flexible element on the diaphragm, bellows, etc. in the working chamber periodically elastic deformation) to make the volume of the working chamber to produce the periodic change. In structure, the reciprocating pump of the working chamber is separated with the outside by means of sealing means, through the pump valve (intake valve and exhaust valve) to communicate with conduit or closed