Power Disconnection and Pressure Relief: Before performing any maintenance or repair work, the power must be disconnected and locked (“Do Not Operate”); ensure that all air pressure in the system has been released and verify that there is no residual pressure.
Draining Lubricating Oil: Stop the machine and drain the lubricating oil from the oil tank. You can start the air compressor and run it for 5 minutes to raise the oil temperature to above 50℃ to reduce viscosity, then slowly open the drain valve at the bottom of the oil-air tank to drain the old oil.
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Removing the Old Oil Seal: Disassemble the motor and coupling, remove the shaft seal cover, and carefully remove the old oil seal.
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Comprehensive Inspection: Check whether the surface of the main shaft is smooth, and whether there is rust, grooves, or wear. If the spindle surface has minor damage, it can be repaired by polishing with fine sandpaper of 800 grit or higher; if the damage is severe, the spindle needs to be replaced.
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Check the sealing surfaces (dynamic ring, stationary ring) for scratches or deformation, and whether the O-rings are aged or broken.
1. Apply sealant: Apply a small amount of sealant evenly to the inside of the removed shaft seal cover plate and spread it evenly with your finger.
2. Press in the new oil seal: Align the brand-new, high-quality oil seal with the cover plate, and use the old ring-shaped bushing to press firmly onto the oil seal, ensuring it fully engages and fits into the groove. Clean up any excess sealant that overflows during pressing.
3. Apply grease: Apply a ring of grease evenly around the inner wall of the oil seal to prepare for lubrication.
4. Treat the main unit end face: Apply a ring of sealant around the outer edge of the main unit mounting end face and spread it evenly with your finger.
5. Assist in installing the cover plate: Find a thin plastic sheet, spray it with lubricant, roll it up, and place it on the spindle as a guide. Adjust the angle of the cover plate with the oil seal installed, align it with the screw holes, and slowly slide it down along the outer ring of the plastic sheet until both ends are in full contact.
6. Tighten the screws: Tighten all screws securely. The tightening torque of the cover plate must strictly follow the requirements of the equipment manual (usually 25-35 N·m), avoiding overtightening or loosening.
Direction Determination: The side with the spring usually faces outward (non-oil side), and the side with letters/model numbers faces outward; reversing the installation will cause instantaneous oil leakage and failure.
Lip Protection: When passing through keyways and threads, a protective sleeve or tape must be used to wrap the lip to prevent sharp edges from cutting the rubber lip (lip damage is a major cause of oil leakage).
Component Selection: Prioritize original or high-quality seals; inferior oil seals are prone to deformation and leakage; always verify the shaft diameter and bearing condition before installation.
Environmental Control: Keep the working surface clean throughout the process; even tiny dust particles entering the sealing interface can cause premature failure. If you lack specialized tools (such as pullers and press sleeves) or are unable to assess the wear condition of the journal, it is recommended to contact professional maintenance personnel to handle the issue and avoid escalating the problem.
Replacing Consumables: Replace the oil filter, clean the oil tank and oil lines, and remove residual sludge and impurities.
Adding New Oil: Inject standard-compliant screw compressor oil through the filler port until the oil level is within the indicated mark, and check for leaks.
Trial Run Testing: Start the air compressor and run it unloaded for 30 minutes, observing for leaks at the shaft end; then run it under load for 1-2 hours, checking for leaks again and monitoring the shaft end temperature to ensure there are no abnormalities.
Controlling Equipment Vibration: During installation, use a level to calibrate the levelness (error ≤ 0.1mm/m), and regularly check the tightness of the anchor bolts; ensure that the alignment deviation between the motor and the main unit coupling is within the allowable range.
Regular maintenance: Ordinary skeleton oil seals should be replaced every 1-2 years, and mechanical seals every 2-3 years (or 8000-10000 hours).
Ensure oil quality: Mixing different brands of lubricating oil is strictly prohibited. Regularly test the oil quality and replace it promptly to prevent impurities from entering the shaft seal and accelerating wear.
Post time: Jul-14-2026
