Rational use of hydraulic oil pumps in the hydraulic system

In hydraulic systems, hydraulic oil pumps are indispensable as the most important power output component. But in hydraulic systems, there are many key points to be aware of when using an oil pump, otherwise it may lead to reduced lifespan or damage to the oil pump.

① Hydraulic oil pumps can be installed with supports or flanges, and the pump and prime mover should use a common foundation support. Both the flange and the foundation should have sufficient rigidity. Special attention: Piston pumps with a flow rate greater than (or equal to) 160L/min should not be installed on the fuel tank.

② Elastic couplings should be used to connect the hydraulic oil pump and the output shaft of the prime mover. It is strictly prohibited to install pulleys or gear driven hydraulic pumps on the hydraulic pump shaft. If pulleys or gears must be connected to the pump, a pair of supports should be added to install them. The coaxiality error between the support and the pump shaft should not exceed 0.05mm.

③ The oil suction pipe should be as short, straight, large, and thick as possible. Generally, a coarse filter with a nominal flow rate not less than twice the pump flow rate (with a filtration accuracy of 80-180 μ m) should be installed in the oil suction pipe. The drain pipe of the hydraulic pump should be directly connected to the oil tank, and the back pressure of the return oil should not exceed 0.05MPa. The suction and return ports of the oil pump must be below 200mm of the lowest oil level in the tank. Special attention should be paid to not installing oil filters on the suction pipe of the plunger pump. The diameter of the shut-off valve on the suction pipe should be one size larger than that of the suction pipe. The length of the suction pipe should be L<2500mm, and there should be no more than two pipe bends.

④ The inlet and outlet of the hydraulic oil pump should be installed firmly, and the sealing device should be reliable, otherwise it may cause air intake or oil leakage, which will affect the performance of the hydraulic pump.

⑤ The self-priming height of the hydraulic oil pump shall not exceed 500mm (or the inlet vacuum degree shall not exceed 0.03MPa). If a supplementary oil pump is used for oil supply, the oil supply pressure shall not exceed 0.5MPa. When the oil supply pressure exceeds 0.5MPa, a pressure resistant sealing ring shall be used instead. For plunger pumps, the reverse flow self-priming method should be used as much as possible.

⑥ Before installing the hydraulic oil pump, it is necessary to check whether the depth of the installation hole is greater than the shaft extension length of the pump to prevent the occurrence of shaft jacking, otherwise the pump will be burned out.