In actual operation, we will find that there are many types of common faults of rotary vane vacuum pump, which can be divided into operation faults and performance faults. In fact, the maintenance skill of rotary vane vacuum pump is that once the vacuum pump has a failure, we need to analyze the cause of the failure, and according to this problem and reason, we can carry out appropriate maintenance of the vacuum pump. This is very critical, and we need to pay attention to it. If the failure is not caused by this reason, you can use the maintenance method corresponding to this failure cause to maintain, which may cause secondary damage to the vacuum pump. Next, I will explain the operation and maintenance of the lower rotary vane vacuum pump, as well as the maintenance methods of common faults.

1、 Operation and maintenance of rotary vane vacuum pump

1. Start the pump

Before starting, check whether the cooling water of the pump is connected. When the ambient temperature is low, the pulley can be moved manually to drain the oil in the pump chamber into the oil tank. Then press the motor button to power on. Pay attention to whether the power supply direction is reversed and whether the pump rotation direction is correct.

2. Precautions for pump operation

Check whether the pump oil volume is near the oil mark; Do not open the valve of the pumped system too fast to prevent a large amount of fuel injection; Pay attention to whether there is abnormal noise and impact sound during operation, pay attention to the oil temperature rise of the pump, and stop the pump immediately in case of local overheating to prevent the pump from jamming or wearing.

3. Precautions for pump stop

When the pump is stopped, it must be vented from the pump inlet (generally, the purchased units have automatic vent valves); Cut off water after power failure.

4. Pump maintenance

Do not mix pump oils of different brands; Determine a reasonable oil change cycle (related to service conditions); When the pump is removed from the system, the pump port shall be sealed to prevent dirt from entering the pump; The required environmental conditions shall be maintained during the use of the pump.

2、 Common faults of rotary vane vacuum pump are as follows:

1. The pump does not rotate. If the situation is unknown, the pump cannot be started first to avoid aggravating the fault. It can be divided into manual turning and non turning.

2. The pump temperature is too high. It means that the high oil temperature measured near the low level exhaust valve exceeds the value in the instruction manual. As the pump temperature increases, the viscosity of pump oil will decrease significantly, and the saturated vapor pressure of pump oil will increase, which will increase the pump pressure and reduce the pumping efficiency; Make rubber parts easy to age; The thermal expansion reduces the running clearance, especially the thickness direction of some non-metallic rotary blades and the clearance of copper sleeve inner hole, which affects the reliability of pump operation. The reason for too high pump temperature may be that the pump temperature 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 volume of water cooling pump is insufficient, and the design effect of circulating water is poor; Failure of temperature control water volume regulating valve, etc.

3. Oil leakage. It can occur at the shaft seal, sealing surface of oil tank and pump parts, drain plug, oil pointer, oil hole bulkhead, through hole connection between stator components and support, gas ballast valve, etc. It can be caused by aging of sealing elements, 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, and the oil may leak if the gas ballast valve is not closed. When making rubber pads, oil resistant rubber must be used according to the original design shape. If the sealing surface is too large, it will leak if it is not pressed tightly.

4. High power exceeds the standard. It can be caused by too high inlet pressure, too high exhaust pressure, seizure of debris entering, too high pump temperature, too small fit clearance of rotary vane, too high voltage, too much pump fluid returning into the pump, etc., which will damage the motor. Long term continuous operation near high power shall be avoided as far as possible. If there is sediment on the surface, it should be removed regularly.

3、 Maintenance skills of rotary vane vacuum pump:

1. Before repairing the vacuum pump, prepare the inspection means.

2. Judge the fault and determine the fault problem. Accurate judgment can save time, and the fault problem shall be verified.

3. When troubleshooting, simplify before complicated, and ease before difficulty. The vacuum pump unit shall not be disassembled if it is unnecessary to disassemble, so as to reduce new damage caused by lack of special tools and improper operation, and reduce change and running in operation time. Generally speaking, the spliced rotor cannot be disassembled, otherwise the form and position tolerance will not be guaranteed and the rotor will be scrapped.

4. For poisonous, harmful and corrosive pumps, please ask users to clean them first and inform them of the protective measures to ensure the health of maintenance personnel.