Possible problems with rotary vane vacuum pumps
1. The pump does not turn. If the situation is unknown, the pump cannot be turned on first, so as not to aggravate the fault. It can be rotated or not rotated by hand.
The pump can turn without rotating. The reason may be that the coupling is faulty; the belt is slipping; the motor wiring is wrong; the motor is damaged;
It cannot be rotated or it is very heavy. The reason may be that the temperature of the starting pump is too low and the viscosity of the pump oil is too high; the design reason is that the pump stops and returns too much oil. If the oil level is too high, the pump stops and returns too much oil (too much refueling, or water vapor condenses in the pump, or the condensed water in the exhaust pipe flows back into the pump); there are foreign objects in the pump (welding in the intake pipe) Slag, oxides; debris of pump parts such as rotary vane springs; the deformation of the rotary vane is stuck; a bite has occurred (copper sleeve, rotor, middle wall, pump cover, stator, bearing).
2. The pump temperature is too high. It means that the maximum oil temperature measured near the primary exhaust valve exceeds the specified value in the instruction manual. As the pump temperature rises, the viscosity of the pump oil will drop significantly, and the saturated vapor pressure of the pump oil will rise, which will increase the ultimate pressure of the pump and reduce the pumping efficiency; make the rubber parts easy to age; heat shrinkage will reduce the running clearance, In particular, the thickness direction of some non-metallic rotary vanes and the inner hole clearance of the copper sleeve affect the reliability of the pump operation. The reason why the pump temperature is too high may be that the ambient temperature of the pump is too high, the intake air temperature is too high, the intake air cooling device fails, and the inlet pressure of the pump is too high for long-term continuous operation; the cooling water of the water-cooled pump is insufficient, and the circulating water design effect is not good; Water regulating valve failure, etc.
3. Oil leakage. It can occur on the shaft seal, the sealing surface of the oil tank and the pump parts, the oil drain plug, the oil mark, the oil hole block, the through hole connection between the stator part and the support. It can be caused by aging of seals, improper installation, damage and failure, uneven surface, impurities, roughness and loose castings. If the oil returns after the pump is stopped, the oil will enter the gas ballast valve. If the gas ballast valve is not closed, oil may leak. When making a self-made rubber pad, you must use oil-resistant rubber. It must follow the original design shape. oil spill.
4. Water leakage. It may occur in the water pipe joints, the surface of the water jacket cover, the water hole screw plug, the water discharge valve, etc., the water jacket is drilled through, the casting is defective, and the crack is frozen, which may also cause water leakage.