Precautions for use of vane pump
Precautions for use of vane pump
① Driven vane pump can use motor or internal combustion engine as prime mover. But the transmission device of the pump can not produce additional axial force and radial force on the transmission shaft of the vane pump.
② The oil suction height of the pump is usually required to be no more than 0.5m. In the pipeline system with long oil inlet pipeline, the oil inlet pipe diameter should be increased to avoid too large flow resistance and poor oil suction, which will affect the working performance of the pump. It should be noted that the connection flange, the joint and the entire oil suction pipeline must be strictly sealed to prevent leakage, so as to avoid noise and system vibration, and create a large number of bubbles in the tank and reduce the service life of the pump. When mineral hydraulic oil is used as working medium, nitrile rubber seal should be used; when phosphate ester is used as working medium, fluororubber seal must be used.
③ Oil selection and filtration, the type and brand of oil should be selected in strict accordance with the product sample of the pump, in order to extend the service life of the pump. For vane pump, it is recommended to use anti-wear hydraulic oil, the viscosity range is 17 ~ 38mm2gs, 24mm2gs.
The oil shall be kept clean, and the filtration accuracy of the system shall not be less than 25um. An oil filter with a filtration accuracy of 70-150um shall be set outside the oil suction port to prevent the inhalation of dirt and impurities. It should be noted that in order to meet the requirements of rapid response, some vane pump products are not allowed to use the suction port filter, and the bypass, return oil and pressure line filter are recommended.
④ Installation, operation and maintenance
i. When the pump is installed horizontally, the pressure port should be installed laterally or upward; the oil suction port should be installed laterally or downward. If the working speed of the pump is low, the suction port of the pump should be installed upward so that it is easy to absorb oil when starting; the oil drain port should always be installed upward. When installed vertically, the shaft end of the pump drive shaft should be upward.
II. The support (seat) of the pump shall be firm, rigid and able to fully absorb vibration. Mounting parts such as Bell mount (flange), coupling and mounting bracket (Fig. f) can be purchased directly from the pump manufacturer.
III. the coaxiality of the transmission shaft and prime mover shaft of the pump should be controlled within 0.1 mm, and flexible coupling should be used as far as possible to avoid bending moment and axial load on the pump shaft. The steering of transmission shaft shall meet the product requirements.
IV. the suction pipe diameter of the pump shall not be less than the inlet diameter of the pump, and the flow through the oil suction filter shall not be less than twice the rated flow of the pump.
5. The value of suction pressure at the pump suction port should meet the requirements of the product manual. If the pump is installed higher than the oil tank, the height from the suction port to the oil level varies with the working medium, which should meet the requirements of the manual.
Vi. the oil drain pipe must be directly led into the oil tank without throttling, and cannot be connected with other oil return pipes. The end of the oil drain pipe must be below the lowest liquid level of the oil tank, and as far away from the oil suction port as possible, so as to ensure that the oil in the pump shell will not be drained in the shutdown state, and the hot oil mixed with air should be avoided to enter the system circulation. Similarly, when the pump is immersed in the oil tank for installation, the installation of the oil drain pipe should also form a siphon effect to ensure that the shell is always full of oil. Generally, the pressure of oil drain (shell) shall not exceed 0.2MPa, the length of oil drain pipeline shall not exceed 2m, the minimum diameter shall be selected according to the oil port specification of the pump, and the low-pressure straight through pipe joint with the largest diameter shall be selected.
VII. The oil tank shall be provided with partition board to separate the air bubbles and dirt brought by the return oil. The oil return pipe should be extended below the liquid level (not directly connected with the pump inlet) to prevent bubbles caused by oil return splash.
b. Start up
i. Before starting the pump, check the inlet, outlet and steering, and the rotation direction of the pump shall be consistent with the direction indicated on the product label.
II. Before the initial start-up, the casing of the pump should be filled with oil (through the oil drain port), and the coupling should be rotated by hand, which should be uniform and flexible. When starting for the first time, the system should be operated without liquid. The purpose is to fill the system with liquid and exhaust the pump and pipe. The system can be pressurized only after the air in the system is drained.
III. during the initial operation or restart after a long-term shutdown, there will be air absorption, so the exhaust valve should be installed at the output end, or the outlet flange should be slightly loosened to remove air, and the test run should be carried out under no-load condition as far as possible.
IV. when adjusting the displacement of variable vane pump, loosen the lock nut first, then rotate the adjusting screw, and pay attention to the direction of rotating the adjusting screw when increasing or decreasing the displacement. After adjustment, tighten the nut. When adjusting the pressure of variable vane pump, attention should also be paid to the correct direction of the pressure regulating screw when increasing and decreasing the pressure. After adjustment, the nut should be tightened.
i. After the pump is purchased, if it is not used for the time being, it is necessary to inject anti rust oil into the pump and coat the exposed surface with anti rust oil, then cover the oil port dust cover and keep it properly.
II. When piping, pay attention to remove the iron filings, residues, cotton yarn and other foreign matters left in the oil tank and pipeline, so as to avoid pump failure.
III. the pressure regulating value of the safety valve of the hydraulic system should not be too high, generally not more than 1.25 times of the rated pressure of the pump.
IV. continuous operation of the pump at too high or too low temperature should be avoided. If necessary, the oil temperature should be adjusted by setting heat exchanger (cooler and heater).
5. Maintain the normal liquid level of the oil tank and replenish the oil in time.
Vi. regularly check the performance of the oil, and timely replace and clean the oil tank if it fails to meet the specified requirements.
VII. The filter should be checked and cleaned frequently to ensure that the pump can absorb oil smoothly.
VIII. After the pump works for a period of time, the mounting screw or flange screw of oil inlet and outlet may be loose due to vibration. Pay attention to check and tighten it.
IX. for vane pump with spare parts of pump core, normal maintenance only needs to replace the pump core. When replacing, pay attention to check whether the sealing ring is flat to prevent edge cutting. When tightening the connecting screws of the shell parts, gradually tighten them in the diagonal direction with uniform force.