There are two reasons for excessive heating of hydraulic pumps, one is mechanical friction heating. Since the moving surface is in a state of dry friction or semi-dry friction, the moving parts rub against each other to generate heat. The second is liquid friction heat. High-pressure oil leaks into the low-pressure chamber through various gaps, and a large amount of hydraulic energy is lost into heat. Therefore, the correct selection of the gap between the moving parts, the oil tank volume and the cooler can eliminate the phenomenon of excessive heating and excessive oil temperature of the pump. In addition, the oil return filter is blocked and the back pressure of the oil return is too high, which will also cause the oil temperature to be too high and the pump body to overheat.
The main reasons for oil leakage in the plunger pump are as follows: (1) the spindle oil seal is damaged or the shaft is defective or scratched; (2) The internal leakage is too large, causing the pressure at the oil seal to increase, and the oil seal is damaged or flushed out; (3) The oil drain pipe is too thin and long, so that the seal leaks oil; (4) The external oil pipe of the pump is loose, the pipe joint is damaged, and the sealing gasket is aging or cracked; (5) The bolt of the variable adjustment mechanism is loose and the seal is broken; (6) The cast iron pump casing has sand holes or poor welding.
