Constant variable pump reaches the set pressure in the pump body before starting level variables, then flow into a steep decline line decreased. Constant power variable pump is almost full pressure phase are variable, constant output power basic guarantee within a certain range , but within the range of the pump set power, pressure rises, the flow is full flow output, when it exceeds this pressure, the flow rate begins to drop, in order to ensure a constant output power (which is to say when manually variable pump below the rated power, the actual use of power is not constant). There are electronically controlled variable displacement pump, it's a variable curve, pressure has nothing to do with the actual decision by the electronic control part. No matter what, the power to match the motor and pump, must be considered. Each piston pump a plunger acting out the drain when the pressure increased, the drain acting position just in the bottom of the plunger to the bottom every time the drain at the top of the hemisphere will be forced out, so hemisphere action. Increased pressure, the higher, the more will be out the top hemisphere excavator variable pump, the smaller the angle of inclination of the hemisphere, the flow of oil will be smaller, it can be said reduction and increased pressure variable pump, the flow is at the same time a. When the oil encountered load, is exactly equal to the desired pressure pump if the maximum pressure that can be output, and that the system pressure is equal to the set pressure pump. Equilibrium, if the pressure is less than the maximum output of the pump pressure required, nor is it not variable, there is a certain variable, but not all of the variables. If the pressure is greater than the desired maximum output pressure of the pump, the pump also reaches the maximum set pressure, to maintain the pressure in the domestic variable pump with other system components, will not be damaged. The above, you might look out of the variable displacement pump is not only the highest and lowest output setting, but the linear variable output, at different pressures transform different output displacement. Sales of variable pump, hydraulic creating crystal quality assurance (certified), Liaocheng Jinan crystal by creating variable pump 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.