Two-stage rotary vane vacuum pump maintenance methods and instructions

Rotary vane vacuum pump type, characteristics, the current situation. Understand the requirements, determine the repair target. 1. Before testing, prepare the test method. 2. To determine the fault, diagnosed the fault. Judgment, may save trouble. Confirmed to verify. 3. Troubleshooting, first simple and complex, the first easy hard. Do not disassemble without demolition. Vacuum pump unit to reduce due to the lack of special tools and improper operation caused by new damage, reduce the change and run-in time. In general, the splicing rotor is not removable, otherwise the form of tolerance can not be guaranteed, the rotor scrapped. 4. Poisonous, harmful and corrosive pumps should be cleaned first by users and the necessary protective measures should be given to ensure the health of maintenance personnel. 5. Fault classification The fault is divided into operational failure and performance problems. Operation failure can include pump does not turn, the pump temperature is too high, oil spills, water leakage, the maximum power exceeded. Performance failure can include the ultimate pressure, extreme pressure, suction efficiency, noise, fuel injection, gas town performance, etc. can not meet the requirements or not. 6 fault diagnosis and diagnostic examples (1) the pump does not turn. Unknown circumstances can not be opened pump, so as not to aggravate the fault. Can be used to move hands and can not move. â‘  pump can move without turning. The reason can be coupling failure; skidding; motor wiring is wrong; motor damage; no power and so on. â‘¡ can not panic or plate up very heavy, the reason can be because the starting pump temperature is too low, the pump oil viscosity is too high; design and manufacture of pump stop too much oil. Water ring vacuum pump is too high caused by the pump back to the oil too much (too much fuel, or water vapor condensation in the pump, or condensate in the exhaust pipe back to the pump); foreign body in the pump (intake manifold In the welding slag, oxide; Spinneret spring pump parts such as debris; Rotary deformation stuck; occurred occlusion (copper sleeve, rotor, the wall, pump cover, stator, bearings). (2) the pump temperature is too high. Refers to the lowest measured near the exhaust valve exceeds the maximum oil temperature manual value. As the pump temperature will increase the viscosity of the pump oil dropped significantly, and to increase the saturated vapor pressure of the pump oil, the pump to increase the pressure limit and reduce the suction efficiency; rubber parts easy to aging; thermal expansion of the running gap narrowed, especially Is the thickness of some non-metallic rotary vane and copper sleeve hole clearance, affecting the reliability of pump operation. Pump temperature is too high because the pump temperature is too high, the intake air temperature is too high, the intake air cooling device failure, the pump long-term continuous operation inlet pressure is too high; water cooling pump cooling water is insufficient, circulating water design is not good; temperature control water Valve failure and so on. (3) oil spill. Can occur in the shaft seal, the sealing surface of the fuel tank and pump parts, drain plugs, oil standard, hole stuffy head, stator parts and bearing through-hole connections, gas ballast valve (for example, 2X-8) and other parts. Aging by the seal, improper installation, damage failure, the surface is not flat, there are impurities, rough and loose castings caused. If you stop the pump back to the oil, the oil will enter the gas town valve, the gas valve may not leak gas. Homemade rubber mat, be sure to use oil rubber, according to the original design shape, sealing surface is too large when the pressure will leak. (4) Leakage can occur in the water pipe joints, water jacket boring cover plane, drain hole plug, drain valve, etc., water jacket drill wear, casting defects, cracking, may also lead to water leakage. (5) high power exceeded. Can be long-term continuous for the inlet pressure is too high, the exhaust pressure is too high, debris into the occlusion occurs, the pump temperature is too high, the rotary vane with the gap is too small, the voltage is too high, too much pump back into the pump caused, Will damage the motor. Should try to avoid long-term continuous operation near the maximum power. If there is sediment on the surface, remove it regularly. (6) The ultimate pressure is not up to standard. It can be caused by external leakage, internal leakage, blockage of oil hole, poor or deteriorated quality of pump oil, condensable substances such as water vapor, distortion of instrumentation and abnormal pump operation. 2x rotary vane vacuum pump leak more leakage, chemical pump exhaust can see the white steam. There are more bubbles at the oil mark, hand exhaust pressure on the exhaust can feel. Low-level exhaust valve at the surface there are more bubbles. Power will increase. At this time, first check whether the gas ballast valve is closed. As the new pump factory in the pump each port to measure the ultimate pressure, so if the leakage phenomenon, the pump port and piping, valves, containers one by one inspection. Outer shaft seal failure, oil cup oil-free, gas-filled head can also cause leakage. The internal leakage can be caused by the movement gap in the pump, the plane of the exhaust valve seat, the sealing surface of the exhaust valve, the inner shaft seal, the plane of the pump cover, the air inlet pipe and the gas valve seal. Wear, corrosion, bite will increase the operating gap. When the oil hole is blocked, open the oil hole to hear the noise of the pump will be lighter. If the oil seal is good, the exhaust valve may fail if the hand is sucked on the exhaust port. If the pump oil clean, unused long-term storage, open the town valve to purify the water vapor pump. If invalid, should check apricot meter. If the pump oil yellow and white has emulsified, the gas can be fully open the town, adjust the atmosphere to purify the operation, if necessary, the amount of gas into the pump port operation, can speed up the purification process. If other volatile gases or liquids are pumped, please change the oil in time and wash the oil tank if necessary. Some pumps, in the interstital airway will be deposited pump fluid, in order to obtain a good oil change effect, to find ways to drain the pump fluid.