Variable piston pump oil pressure pump, pump casing variable housing through the hole into the inferior vena variable housing through a one-way valve, when the downward movement of the lever, push downward movement of the servo piston, the servo valve the valve port open, the oil pressure of the lower chamber of the housing Variables piston through the hole into the superior vena variable case, since the upper chamber area larger than the lower chamber, hydraulic pressure pushes the piston downward movement repair hydraulic pumps, drive pin the variable head rotates around the ball, changing the inclination angle of the variable head (increase) pump repair, piston pump flow rate increases. On the other hand lever upward movement, change the angle of inclination variable head in the opposite direction of the hydraulic pump repair, pump flow also changes. When the tilt angle changed to zero after the hydraulic pump, the variable angle head to the negative change of direction, the flow generating commutation, pump out the oil port transformation. Overheating hydraulic pump excessive heat for two reasons, one is mechanical friction and heat. Since moving surfaces in dry or semi-dry friction state friction, friction between the moving parts of the heat. The second is a liquid friction and heat. High pressure oil leak to the low pressure chamber through a variety of gap, a large number of hydraulic energy into heat energy loss. Therefore, the correct choice of the gap between moving parts, fuel tank capacity and coolers, can put an end to excessive heat pumps and high oil temperature phenomenon. Also, back to the oil filter blockage caused by excessive back pressure back to the oil, the oil temperature is too high and can cause the pump to overheat. 7. Piston oil spill oil spill following main reasons: (1) the spindle shaft seal is damaged or defective scratch; (2) internal leakage is too large, resulting in increased pressure oil seal, and the seal damaged or out; ( 3) vent pipe too small for too long, so the seal leakage; (4) external pump tubing loose fittings injury, the gasket aging or cracks; (5) variable adjustment mechanism bolts loose, broken seals; (6) Cast casing adverse trachoma or welding. Hydraulic pump repair | hydraulic pumps | hydraulic factory direct crystal hit by the Jinan Jing 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 constantly improving innovative ideas will lead crystal create hydraulic and you hand into the brilliant, for a better future!