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, the constant current pressure spring valve is generally adjusted in advance, not change. Pressure oil pump on the left side all the way to the role of constant valve. Variable pump Training, another way through the role of the right side of the throttle valve and X port 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 position. Variable pump maintenance of telephone, the control piston chamber pressure relief after before pushing the oil cavity pressure 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, the control of oil push control cylinder displacement hydraulic pump is reduced to the position before the change. When the machine running. Variable pump refinement, if dirt clogged pores balancing valve, causing the parking brake can not be released, resulting in walking deviation. Because when the machine is running variable displacement pump, oil pressure, if not through the hole into the balancing valve balancing valve spring chamber to promote balanced valve spool moves, the pressure balance valve oil can not pass through the slot on the hydraulic system into the lead parking brake force can not be lifted, the results can not rotate the motor running, so there walking deviation. Remedy; cleaning Valves; when disassembly, to avoid dirt; regularly replaced to meet the requirements of hydraulic oil and filter. The variable variable pump pump repair phone _ _ creating hydraulic crystal grain provided by Jinan Chong Hydraulic Machinery Co., Ltd .. Jinan Jing Chong Hydraulic Machinery Co., Ltd. (www.jnjcyy.com) (www.jnjcyy.com) strong, credible, in Jinan, Shandong mining machinery industry has accumulated a large number of loyal customers. The company better work attitude and continuous improvement to create innovative ideas will lead crystal hydraulic and you hand into the brilliant, for a better future!