An electric hydraulic pump is a hydraulic component that effectively provides pressurized liquid for hydraulic transmission. The function of an electric hydraulic pump is to effectively convert the mechanical energy of the power machine into the pressure energy of the liquid. The output flow can be adjusted according to demand, which we call a variable pump. The output flow cannot be adjusted, which is called a fixed displacement pump.
1. Working Principle
An electric hydraulic pump effectively converts mechanical energy into fluid pressure energy. It can also be called an energy conversion device. It effectively provides pressurized oil to the hydraulic transmission system. Generally speaking, all pumps used in hydraulic transmission technology rely on alternating volume changes in a sealed working chamber to operate, and are therefore classified as positive displacement pumps.
2. Working conditions
(1) The working chamber of the electric hydraulic pump needs to meet certain conditions. It needs to have sealing performance and a variable working chamber. The volume of the working chamber can increase or decrease repeatedly. When it increases, it is connected to the oil suction chamber. When it decreases, it is connected to the oil pressure chamber. Here we remind everyone that the oil suction chamber and the oil pressure chamber cannot communicate.
(2) The electric hydraulic pump body is small and light, easy to use, and has high working pressure. Single-stage pump station: simple structure, can obtain a higher working pressure. Two-stage pump station: at low pressure, the high and low pressure pumps supply oil at the same time, which can obtain a larger output flow.
(3) At high pressure, the low pressure pump automatically returns oil to the unload relief valve at no load. Reduce power consumption. Pressure maintenance function: when there is no leakage in the external oil circuit, the pump stops and maintains pressure for 5 minutes, and the rated pressure drop does not exceed 5Mpa. According to the commonly used pump structure in the hydraulic system, it is divided into three types: gear pump, vane pump and plunger pump.
3. Applications of Electric Hydraulic Pumps:
(1) Electric hydraulic pumps can be used as hydraulic pumps for various hydraulic equipment.
(2) When equipped with other hydraulic tools, electric hydraulic pumps can be used for lifting, profiling, pipe bending, straightening, shearing, assembly, disassembly, and other tasks, reducing labor intensity and improving work efficiency.
4. Instructions for using the electric hydraulic oil pump:
(1) When using, open the bleed nut, turn on the switch on the oil collecting block, plug in the power supply, and put the quick connector on the quick connector on the hydraulic equipment.
(2) Press the power switch, wait for the motor to run for 1-2 minutes, turn off the switch and put it in the pressurized state. At this time, the output hydraulic oil will perform various tasks. The output hydraulic oil will automatically increase the pressure as the load increases to perform various tasks until it reaches 63MPA.
(3) After the work is completed, turn on the switch to unload the load. After the hydraulic oil returns, remove the quick connector sleeve, screw on the bleed nut, and turn off the switch.
5. Classification of Electric Hydraulic Pumps
There are many types of electric hydraulic pumps. According to the shape and movement mode of the main internal motion structure, they can be divided into three types: gear pumps, vane pumps and plunger pumps.
(1) According to whether the suction and discharge direction of the hydraulic pump can be changed, it can be divided into unidirectional pumps and bidirectional pumps. Single-phase pumps refer to pumps whose suction and discharge directions cannot be changed, while bidirectional pumps can be changed.
(2) According to whether the displacement of the electric hydraulic pump can be adjusted, it can be divided into fixed displacement pumps and variable displacement pumps. Displacement is simply the volume of liquid that can be discharged per rotation of the pump shaft without leakage. The size of the displacement is related to the geometric dimensions of the pump.
6. Maintenance precautions for electric hydraulic pump station:
(1) Use No. 20 engine oil for the oil pump.
(2) The oil storage capacity must be within the range above the oil window.
(3) Every time you add oil or change oil, you must filter it with an oil filter with a mesh size of 80 or above. When changing oil, you must clean the oil tank. The oil change period is six months.
(4) The working oil temperature is 10 degrees Celsius to 50 degrees Celsius.
(5) Before starting the electric pump, you must open the bleed nut and turn the switch to the unloading position.
(6) If the motor temperature is too high during use, stop using it. Let it cool down before using it again.
(7) The pump has been adjusted before leaving the factory and must not be adjusted at will. When it needs to be readjusted, it must be done with the help of a pressure gauge.
(8) The high-pressure oil pipe has been tested at 105MPA before leaving the factory. However, since hoses are prone to aging, users need to inspect them regularly, generally every six months, and three months for frequent use. During the inspection, they should be pressure tested at 87.5 MPa. If there is damage, bulges, or leakage, they cannot be used.
(9) Bearings should generally be cleaned every six months and greased during assembly.