Variable radial piston pump variable displacement pump includes a piston and shaft eccentric eccentric, including a swash plate type axial piston variable displacement pump and Cline - variable motor speed control circuit is equal to the pump speed range and speed range Rp motor speed range Rm seed multiplication circuit for high-power hydraulic system is particularly suitable for systems with two or more hydraulic pumps and hydraulic motors can require separate occasions for speed constant pressure valve is turned on, the pressure on the piston oil into variable chamber, the variable pressure in the lowest piston position, full displacement pump output pressure oil; when the pump when it is set at a constant pressure of the operating variable pump maintenance *, acting on the valve body of the hydraulic thrust is equal to the constant voltage setting adjustment spring force, the constant pressure into the oil discharge port valve is turned on at the same time, the variable hydraulic thrust of the piston is equal to the upper and lower chambers, a variable balanced position in the piston, when hydraulic damping (load) increase, the hydraulic transient elevated, constant pressure valve row oil port open big, oil inlet off small, relatively lower chamber pressure variable piston upper chamber to reduce the variable variable pump piston moves upward telephone service *, pump flow is reduced until the pressure drops to the constant pressure it is set, then the variable piston working in the new equilibrium position. Conversely, if the hydraulic damping (load) decreases, hydraulic transient decrease refinement variable pump *, constant pressure to open the inlet valve large drain port off small, variable on relatively lower chamber hydraulic piston chamber increases, variable piston move down, pump flow increases, the pressure rises until it is set to a constant pressure. Nursing variable pump *, variable pump, hydraulic from Jinan Jing Jing Chong Chong Hydraulic Machinery Limited. 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!