When the hydraulic pressure control slide valve spring force is equal to the left side of the slide valve is closed, the control cylinder stop motion, ending the process variable, the pump working pressure to re-stabilize the setting value in the vicinity of the spring. Similarly, when the system pressure is reduced variable pump · care institutions so that the output variable flow pump is increased work pressure back up to the setting value. To 12 remote pressure control system remote pressure control principle shown in Figure 2, which is basically the same principle with the constant pressure control variable pump · refinement, the only difference is the pressure regulating valve can be installed in any position as needed, so the pump pressure regulating role played remotely. Is the remote pressure control valve, usually direct-acting relief valve, proportional relief valve can also be used. When using proportional relief valve, variable pump pressure by electrical adjustment. Under conditions of constant speed, constant output flow pressure can be mobilized for the variable vane pump, constant pressure and flow are not adjustable for quantitative vane pump. Their biggest difference is that the variable vane pump shaft is installed then the heart. After speaking simple quantitative vane pump speed is selected, he would certainly flow and pressure, it can not recuperate. Output flow variable vane pump according to the hydraulic system pressure changes (external load size) automatically flow conditioning, high output pressure is low flow, low pressure output flow, so that he can save the number of hydraulic components, thus simplifying the hydraulic system, and can reduce oil heat. The disadvantage is that the flow pulsation serious variable pump, the hydraulic system pressure poised, short life of the pump, pump bearings easily broken, because he was then the heart of the installation, and the big pump bruit. By conditioning eccentricity vane pump, piston slide angle can be achieved through the conditioning variables. Quantitative vane pump works: sealed volume of the stator and rotor valve plate is composed of blade divided into several, one week per revolution of the rotor, each sealed space complete two suction and pressure oil pump · maintenance variables, it is called Quantitative vane pump. Variable vane pump works: variable vane pump can pitch by changing rotor and stator eccentricity e conditioning pump flow to the hydraulic system at work feeding the energy use of justice, the effectiveness of the high, low temperature of the oil. Eccentric actually change from e achieved only by moving the stator, the rotor and shaft position is the prime mover of the axis defined by the variable displacement pump · Hydraulic record grain refinement _ (certified) _ variable pump from Jinan crystal Chong Hydraulic Machinery Limited. Jinan Jing Chong Hydraulic Machinery Co., Ltd. (www.jnjcyy.com) (www.jnjcyy.com) Shandong Jinan, mining machinery leaders, over the years, the company is implementing the scientific management, innovation and development, the principle of honesty and trustworthiness, the maximum meet customer needs. In the crystal to create a hydraulic leadership with the staff warmly welcome all inquiries negotiations to create the crystal to create a better future for the hydraulic.