Flow control variable pump control principle, in which a control slide valve, for the pressure springs 2, 3 is a control cylinder, 4 is a throttle valve (typically proportional valve), 1 and 2 collectively known constant flow valve. Variable pump pressure spring maintenance, constant valve is generally adjusted in advance, not change. Pressure oil pump action all the way on the left side of the constant flow valve, the other way through the right side of the throttle valve and X port role in constant valve. Because after the throttle valve, the control oil pressure constant flow valve there are left and right ends of the pressure differential. When the load pressure increases, the right end of the control oil pressure constant flow valve plus differential pressure of the spring is greater than the set pressure of the left end of the pilot oil pressure, constant flow valve is switched to the right end position, the control piston back pressure relief chamber, the front chamber pressure oil push control cylinders right line, increasing displacement hydraulic pump, hydraulic pump discharge pressure increases, constant pressure to increase oil control valve left, constant valve is switched to the left position. Variable Pump Specialist, control oil cylinder push control displacement hydraulic pump is reduced to the position before the change. When the motor is working pressure is lower than the initial pressure variable pressure, constant pressure control servo valve 7 function in the left position, the servo valve 7 is a section of the oil passage, motor complete control by the pilot pressure. At this point, the big variable cylinder chamber oil passage is closed, the motor will maintain the current displacement. When the motor is operating pressure continues to rise, the servo valve 7 will be in function of the position of the left position, the variable cylinder large low pressure oil chamber and connected, variable piston pump will move to the right under the action of a small variable pressure oil chamber, the motor row volume increases. We know that. Variable pump refinement, if the load torque due to the reason or due to a decrease in the swing angle motor system pressure increases, when it reaches the set value of the constant voltage control, motor pendulum to swing angle larger. When the external load decreases, the motor control process with the above process is reversed, not repeat them here. In short constant voltage control function of the motor is automatically changed according to changes in external load motor displacement, so that the motor operating pressure is kept within the set range. The variable hydraulic pump maintenance _ Jing Chong (certified) _ variable pump from Jinan Jing 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.