Rotary vane vacuum pump maintenance skills

In actual operation, we will find that there are many types of common faults in rotary vane vacuum pumps, which can be divided into operation faults and performance faults. The maintenance technique of rotary vane vacuum pump is actually that once the vacuum pump fails, we need to analyze the cause of the failure, and then carry out appropriate vacuum pump maintenance according to the problem and reason. This is very critical and needs to be paid attention to by everyone. If you use the maintenance method corresponding to the cause of the failure to maintain the failure caused by this reason, it may cause secondary damage to the vacuum pump. Next, the editor 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

⒈ Start of 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 by hand to make the oil in the pump cavity drain into the oil tank. Then press the motor button to send power, pay attention to whether the direction of the power supply is reversed, and whether the direction of rotation of the pump is correct.

⒉ Precautions for pump operation

Check whether the oil level of the pump is near the oil mark line; 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, and pay attention to the increase of the oil temperature of the pump. Immediately stop the pump in case of local overheating to prevent pump sticking or wear.

⒊ Precautions when stopping the pump

When the pump is stopped, the air must be amplified from the pump inlet (generally purchased units have an automatic air release valve); after the power is cut off, the water is cut off.

⒋Maintenance and maintenance of the pump

Do not mix pump oils of different brands; set a reasonable oil change interval (related to the conditions of use); when the pump is removed from the system, the pump port is sealed to prevent dirt from entering the pump; the pump should be kept in use as required environmental conditions.

Second, the common faults of rotary vane vacuum pump are as follows:

1. The pump does not turn. If the situation is unclear, the pump cannot be turned on first, so as not to aggravate the failure. It can be divided into those that can be moved by hand and those that cannot be moved by hand.

2. The pump temperature is too high. Refers to the high oil temperature measured near the low-level exhaust valve exceeding the value in the instruction manual. As the pump temperature rises, the viscosity of the pump oil will be greatly reduced, and the saturated vapor pressure of the pump oil will increase, which will increase the pressure of the pump and reduce the pumping efficiency; make the rubber parts easy to age; thermal expansion will reduce the operating gap, especially The thickness direction of some non-metallic rotary vanes and the gap between the inner holes of the copper sleeve affect the reliability of the pump operation. The reason why the pump temperature is too high can be that the pump temperature is too high, the intake air temperature is too high, the intake air cooling device fails, the inlet pressure of the pump is too high for long-term continuous operation; the cooling water volume of the water-cooled pump is insufficient, and the circulating water design effect is not good; the temperature control water volume Control valve failure, etc.

3. Oil leakage. It can occur in the shaft seal, the sealing surface of the oil tank and the pump parts, the oil drain plug, the oil mark, the oil hole plug, the connection between the stator part and the through hole of the support, and the gas ballast valve. It can be caused by aging of seals, improper installation, damage failure, uneven surface, impurities, roughness and loose castings. If the oil is returned 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 self-made rubber pads, oil-resistant rubber must be used, and the original design shape should be used. If the sealing surface is too large, it will leak oil if it is not pressed tightly.

4. The high power exceeds the standard. It can be caused by long-term continuous operation that the inlet pressure is too high, the exhaust pressure is too high, the debris enters the occlusion, the pump temperature is too high, the matching gap of the rotary vane is too small, the voltage is too high, and the pump fluid returns to the pump too much, etc. damage the motor. Long-term continuous operation near high power should be avoided as much as possible. If there are deposits on the surface, it should be disassembled regularly to remove.

Three, rotary vane vacuum pump maintenance skills:

1. Before the maintenance of the vacuum pump, prepare the detection means.

2. Determine the fault and determine the fault problem. The judgment is accurate, it can save trouble, and the fault problem needs to be verified.

3. Troubleshooting, first simple and then complex, first easy and then difficult. No need to disassemble the vacuum pump unit to reduce the new damage caused by the lack of special tools and improper operation, and reduce the change and running time. Generally speaking, the spliced ​​rotor is not removable, otherwise the geometrical tolerance will not be guaranteed, and the rotor will be scrapped.

4. Toxic, harmful and corrosive pumps, users should be asked to clean them first, and inform them of protective measures to ensure the health of maintenance personnel.