working principle
    The body portion (see the cross-sectional structure) driven by a shaft rotating cylinder, uniformly distributed in the cylinder block about the shaft center line of the plunger is rotated seven, through the center post spring assembly slide shoe against the first variable ( or swash plate) on. Thus, with the rotation of the cylinder and the piston reciprocates complete oil suction and pressure operation. The pump is to rely on internal control (you can also use external control) manipulated variable hydraulic mechanism. The pump pressure adjustment range is relatively small, after the oil pressure generated in the 3 ~ 4Mpa variable, the flow High flow decreases rapidly to the desired value. This pump is actually equivalent to a combination of high and low pressure pumps, pump drive power selection may reference pressure compensated variable pump power selection method to calculate.
     High-pressure oil from the main body portion, the lower flange into the lower chamber (d), when the spring force is greater than the role of fluid pressure in the area of the lower end of the push rod and push variable piston moves downward, the pump flow rate increases. When the area of the lower end of the push rod acting on the liquid pressure is greater than the spring force, the piston moves upward variables, the pump flow is reduced. When adjusting variable characteristics, according to the scope of the required flow and pressure changes, adjust the setting sleeve, so that the ultimate pressure of the pump flow rate changes do not occur, then adjust the pump flow rate adjustment screw so that the initial pressure change just happened to meet the requirements.