11 precautions for the use of the hydraulic pump of the four-column hydraulic press

- Jun 28, 2020-

1) Precautions for hydraulic pump connection of four-column hydraulic press

① The hydraulic pump of the four-column hydraulic machine can use the support or flange equipment. The pump and the prime mover should use the same base support. Both the flange and the base should have sufficient rigidity. Special attention: plunger pumps with a flow rate greater than (or equal to) 160L/min should not be installed on the tank.


② Flexible couplings should be used between the hydraulic pump of the four-column hydraulic machine and the output shaft of the prime mover. It is forbidden to drive the hydraulic pump of the four-column hydraulic machine with a wheel or gear on the hydraulic pump shaft of the four-column hydraulic machine. When the pump is connected, a pair of supports should be added to the equipment pulley or gear. The coaxiality error between the support and the pump shaft should not be greater than Φ0.05mm.


③ The oil suction pipe should be as short, straight, large, and thick as possible. The oil suction pipe generally needs to be equipped with a coarse filter with a nominal flow rate not less than 2 times of the pump flow rate (the filtration accuracy is generally 80~180μm). The oil drain pipe of the hydraulic pump of the four-column hydraulic machine should be directly connected to the oil tank, and the backpressure of the oil return should not exceed 0.05MPa. Both the oil suction pipe port and the oil return pipe port of the oil pump must be below 200mm of the lowest oil level of the oil tank. Pay particular attention to the fact that the oil filter of the plunger pump does not allow the device oil filter. The diameter of the stop valve on the oil suction pipe should be one block larger than the diameter of the oil suction pipe. The length of the oil suction pipe is L<2500mm, and there are no more than two pipe elbows.


④ The hydraulic pump inlet and outlet of the four-column hydraulic machine should be sturdy and the sealing equipment should be firm, otherwise air suction or oil leakage will occur, affecting the function of the hydraulic pump of the four-column hydraulic machine.


⑤ The self-priming height of the hydraulic pump of the four-column hydraulic machine does not exceed 500mm (or the inlet vacuum does not exceed 0.03MPa). If the fuel pump is used for oil supply, the oil supply pressure should not exceed 0.5MPa. When the oil supply pressure exceeds 0.5MPa, it should be used instead. Pressure-resistant sealing ring. Regarding the plunger pump, the backfill self-priming method should be selected as much as possible.


⑥ Before installing the hydraulic pump of the four-column hydraulic machine, check whether the depth of the equipment hole is greater than the shaft extension of the pump to avoid the phenomenon of jacking, otherwise, the pump will be burned.


(2) Precautions for the use of hydraulic pumps by four-column hydraulic machine manufacturers

① When the hydraulic pump of the four-column hydraulic machine is started, it should be jogged several times first. After the oil flow direction and sound are normal, work under low pressure for 5 to 10 minutes, and then put it into normal operation. Before the plunger pump is started, it is necessary to fill the pump with clean working oil through the drain port on the casing.


② The viscosity of the oil changes with the influence of temperature, and the viscosity decreases with the increase of oil temperature. Therefore, the oil temperature should be kept below 60℃. In order to make the hydraulic pump of the four-column hydraulic machine work stably at different operating temperatures, the selected oil The fluid should have oil temperature characteristics whose viscosity is less affected by temperature changes, as well as better chemical stability and anti-foaming functions. 


It is recommended to use L-HM32 or L-HM46 (GB11118.1-94) anti-wear hydraulic oil.

③ The oil must be clean, and must not be mixed with mechanical impurities and corrosive substances. The hydraulic system without filtering equipment on the oil suction line must be refueled to the fuel tank through an oil filtering vehicle (filtering accuracy less than 25μm).


④ The maximum pressure and maximum speed of the hydraulic pump of the four-column hydraulic machine refer to the peak value allowed in a short period of time during operation. Avoid long-term use, otherwise, it will affect the life of the hydraulic pump of the four-column hydraulic machine.


⑤ The normal operating oil temperature of the hydraulic pump of the four-column hydraulic machine is 15 to 65°C. The maximum temperature on the pump casing is generally 10 to 20°C higher than the oil temperature at the pump inlet in the oil tank. When the oil temperature in the oil tank reaches 65°C, the pump The maximum temperature on the shell does not exceed 75~85℃.