Molecular Pump of Trouble and Treatment

Molecular pump is a kind of vacuum pump that uses a high-speed rotating rotor to transmit momentum to gas molecules, so that they can obtain a directional speed, which is compressed and driven to the exhaust port and then pumped away for the front stage. Since the profile groove of the simple traction pump is opened on the outer surface of the rotor cylinder or the inner surface of the pump, the higher linear velocity of the outer cylinder of the cylinder can be fully utilized to transfer the momentum of the gas molecules and improve the pumping effect of the pump.

About molecular pump troubleshooting

1.Why is the molecular pump half hot and half cold?

Reason: There is sunlight or other heat sources nearby

Solution: Avoid light or heat sources

2.The oil turns black during the use of the molecular pump. Why does the oil turn black? Or how long does it take for the oil to turn black?

Reason: poor cooling, too much load

Solution: Check the cooling system, check the vacuum system

3.During the operation of the molecular pump, the frequency dropped from normal to a certain frequency, then returned to normal, and then dropped to a certain frequency, and then returned to normal, repeatedly, the phenomenon is still the same after replacing the power supply, what is the phenomenon? explain?

Reason: The load is too large and the system vacuum is not enough

Solution: Check the system

4.Why does the molecular pump bearing burn out? Reasons: ① Lack of regular maintenance ② Poor cooling leads to overheating ③ Failure to change oil in time ④ The extracted gas contains a lot of dust Solution: ① maintain in time ② check the cooling system ③ change oil in time ④ isolate dust

5.With the protection of the protective net, why are there still large pieces of broken glass falling into the pump?

Reason: The protective net is broken, the front pipeline is broken

Solution: Optimize system design

6.When the vacuum degree is very good, why does the molecular pump oil return to the fore-stage pipeline?

Reason: oil pool rupture or poor seal

Solution: Check the oil pool

7.Why does the molecular pump oil pool crack or deform under normal use?

Reason: overheating, heavy load

Solution: Check the cooling system, check the system

8.The top wire, screw and other objects often fall out of the molecular pump, such as the top wire of M5. Does it affect the use of the molecular pump? How should it be resolved? Reason: It should be an occasional thing, it may be a balance nail missed in the balance, and it has no effect on the molecular pump.

Solution: It should be an occasional thing, it may be a balance nail that is missed in the balance, and it has no effect on the molecular pump.

9.How many calipers should be used for the apron molecular pump, and it is safe to use? A: There is no special limit, at least 3, according to the flange size, 3, 6, 12, 24, etc. can be selected

10.Under what circumstances will the inverter power supply cause program loss or confusion?

Answer: ① Voltage instability ② Strong interference ③ High voltage ignition ④ Artificial decryption

11.How to define the noise of molecular pump? Are there eligibility criteria and what is it?

Answer: If less than 72db is qualified, the size of the noise is not well defined, and special equipment and a specific test environment are required.

12.Does the molecular pump have clear requirements for cooling? What is the outside temperature required for air cooling? If water cooling, what are the specific requirements for water? What are the consequences if the requirements are not met?

Answer: Pay attention to the water temperature and water flow. Poor cooling will cause unprovoked shutdowns, broken pumps, and black oil.

13.The molecular pump power supply has problems such as grounding and shielding. What should be the best way?

Answer: The power supply itself has a grounding wire, and it is only necessary to ensure that the city network is well grounded; shielding mainly refers to the shielding of strong magnetic fields and strong radiation.

14.The inverter power supply will automatically shut down when the speed increases, that is, it will display “Poff”?

Answer: Reason: Low voltage

15.Reasons for broken blades of molecular pump:

Answer: There are many reasons for the broken rotor and stator of the molecular pump, which can be summarized as follows:

①, Misoperation; such as sudden vacuum breaking, because the gap between the rotor and the stator blade is very small, if the material of the blade is relatively thin or soft, the sudden air resistance will cause the blade to deform, which may cause the rotor and stator to be deformed. friction between them, resulting in breakage.

②, it is a foreign object falling in; it is definitely not possible without a filter screen, and the thing that falls in does not have to be big, but if the hardness is enough, it will cause damage, and the edge of the blade will be smashed into a jagged shape, and it will be broken. blade. Therefore, the current equipment manufacturers will try to install the molecular pump at a 90-degree side or upside down when installing the molecular pump to prevent foreign objects from falling into it.

③ The voltage is unstable, especially for the molecular pump of the maglev type.

④. The efficiency of the backing pump is poor; we know that most of the gas in the cavity is first pumped out by the backing pump, and the molecular pump will only start when the vacuum reaches a certain level. If the efficiency of the backing pump is poor, the molecular pump will be more laborious, the startup speed will be slow, the pumping time will be long, the current will be high, and the temperature of the molecular pump will increase.

⑤ The dynamic balance of the molecular pump during maintenance is not done well, which is the key to the technology. Poor dynamic balance results in large vibration, poor pumping efficiency, and easy to cause excessive wear of the bearing part.

⑥, the bearing part does not use the original standard bearing, the effect and size are not standard, etc.