I. First, Grasp the Basic Knowledge of Molecular Pumps

Q1. How does a High Vacuum Molecular Vacuum Pump work?

A1: Simply put, it relies on the high-speed rotating rotor or moving parts inside to "carry" gas molecules along, expelling the gas step by step until a high-vacuum state is achieved. The principle basically uses the collision and inertia generated by mechanical movement — it’s like "giving a hard push" to gas molecules, forcing them to move toward the pump’s outlet. That’s how it efficiently pumps out the gas.

Q2. What are the common types of molecular pumps?

A2: There are mainly a few types: ion pumps, turbo-molecular pumps, shielded static molecular pumps (such as rolling rotor pumps), and spiral pumps. Different types of pumps are suitable for different vacuum levels and scenarios. For example, ion pumps can handle ultra-high vacuum environments, while rotary molecular pumps are more suitable for high-vacuum situations.

II. How to Perform Daily Maintenance?

Q3. What does daily maintenance of molecular pumps involve?

A3: Usually, you need to take care of these aspects:

• Check and replace grease and lubricants

Ensure the lubrication system has enough oil to reduce mechanical wear.

• Inspect vacuum seals

Check if there’s air leakage from O-rings and sealing surfaces.

• Clean filters and strainers

Prevent dust and impurities from entering the pump interior.

• Examine the cooling system

Make sure cooling water flows smoothly to avoid pump overheating.

• Monitor lubricating oil

Regularly check the oil quality and oil level, and replace the oil if necessary.

Q4. How to ensure long-term stable operation of a molecular pump?

A4: Just do these things well:

Have professionals conduct regular inspections to spot potential issues early.

Keep the equipment clean to avoid dust and oil buildup.

Perform lubrication and seal inspections according to regulations.

Control the system’s electrical parameters to prevent equipment overload.

Avoid sudden power outages or abnormal operation.

III. How to Troubleshoot Faults?

Q5. If a molecular pump fails to start or is hard to start, what might be the causes? How to check?

A5: The main causes are as follows:

Power failure or wiring problems.

Faults in the motor or drive system.

Automatic shutdown of the protective relay.

Jammed rotor or mechanical faults.

Incorrect parameter settings in the control system.

For troubleshooting, you can do this:

First, check if the power supply is normal and if the indicator lights on the control panel are working correctly.

Inspect the motor wiring and fuses.

Manually rotate the rotor to see if it’s jammed.

Check the protective devices and parameter settings.

If all else fails, use a multimeter to test the motor windings.

Q6. Why does a molecular pump’s pumping speed slow down or fail to reach the expected vacuum level?

A6: Possible causes:

Pump oil has thickened or accumulated contaminants.

Severe wear on the rotor or sealing components.

Aging O-rings or air leakage.

Clogged filter.

Leakage in the vacuum system.

For troubleshooting:

Check the oil level and quality, and replace the oil if needed.

Inspect the mechanical parts to see if the rotor is balanced and the seals are intact.

Use helium to test for leak points.

Clean or replace the filter.

Turn off the pump and check the overall sealing condition of the system.

Q7. If a molecular pump has abnormal vibration or loud noise, how to check?

A7: Possible problems are here:

Unbalanced rotor or foreign objects stuck inside.

Damaged rotor bearings or insufficient lubrication.

Loose mechanical supports.

During troubleshooting:

First, cut off the power, then carefully disassemble and inspect the rotor and bearings.

Check if the rotor is balanced; re-calibrate it if necessary.

Inspect if the support and fixing bolts are loose.

Remove foreign objects and ensure the internal operating space is clean.

Q8. If the pump oil changes color or has an unusual smell, does it mean the oil needs to be replaced?

A8: Yes. If the oil darkens, has a strange smell, or thickens, it probably means the oil is contaminated or deteriorated — you should replace it promptly. Contaminated or aged oil will affect the pump’s pumping performance and worsen mechanical wear.

Tips for oil replacement:

Replace the oil according to the cycle specified in the equipment manual.

Use high-quality lubricating oil recommended by the manufacturer.

Keep the oil circuit and filters clean.

IV. What to Note for Preventive Measures?

Q9. What safety precautions should be taken during maintenance?

A9: Remember these points:

Disconnect the power supply and make sure the equipment is stationary before starting maintenance.

Avoid touching high-speed rotating parts to prevent injury.

Use appropriate tools to avoid damaging the equipment.

Wear gloves and safety goggles when replacing oil.

After operation, ensure all covers and casings are properly sealed.

Q10. How to extend the service life of a molecular pump?

A10: Just do these things well:

Perform regular maintenance and inspections as recommended by the manufacturer.

Avoid overloading the pump.

Use manufacturer-recommended parts and lubricating oil during maintenance.

Ensure the system is well-sealed to reduce leakage.

Detect and fix potential faults in time to prevent small issues from turning into big ones.