Atlas Copco Gear Casing Seal Kit Replacement – 2906065800

The Atlas Copco 2906065800 Gear Casing Seal Kit is used to restore the sealing of the gearbox/gear casing in ZR/T 55–90 compressors. The gear casing houses rotating gears and related components, while the seals help maintain the required internal lubrication and prevent leakage or contamination.

Working Process

1. Power Transmission – The compressor drive system rotates the gearbox gears.
2. Gear Rotation – The gears transfer rotational power to the compressor elements.
3. Lubrication – Internal gear components operate with the required lubrication.
4. Gear Casing Sealing – Sealing components close the casing and connection points.
5. Leak Prevention – O-rings and seal washers prevent lubricant from escaping.
6. Contamination Protection – The seals help prevent dirt and moisture from entering the gear casing.
7. Continuous Operation – The sealed gear casing maintains reliable operation during continuous compressor service.

Main Functions

• Seals the gear casing.
• Prevents lubricant leakage.
• Helps prevent contamination.
• Maintains proper internal lubrication.
• Supports reliable gear operation.
• Replaces worn sealing components during maintenance.
• Helps extend gearbox service life.

Kit Components

A ZR/ZT parts list identifies 2906 0658 00 as the Gearcasing Seal Kit and lists sealing components including O-rings and seal washers.

Possible Failure Symptoms

A worn or damaged gear-casing seal can cause:

• Lubricant/oil leakage.
• Contamination entering the gear casing.
• Reduced lubrication quality.
• Increased gearbox temperature.
• Abnormal gear noise.
• Increased vibration.
• Premature gear or bearing wear.

Maintenance Procedure

1. Shut down the compressor according to the applicable Atlas Copco service procedure.
2. Isolate the electrical supply.
3. Fully depressurize the compressor.
4. Allow the equipment to cool.
5. Drain/isolate the relevant lubricant circuit.
6. Open the gear-casing service area.
7. Remove the old O-rings and seal washers.
8. Inspect the casing and sealing surfaces for damage.
9. Clean the mating surfaces.
10. Install the replacement seals from 2906065800.
11. Ensure all O-rings are correctly seated without twisting.
12. Install the seal washers in their correct positions.
13. Reassemble the gear casing according to the specified torque sequence.
14. Restore the lubricant circuit.
15. Restart the compressor.
16. Check for leakage, abnormal noise and vibration.
17. Verify normal operating temperature.

Technical Summary

Recommended catalog title:
Atlas Copco 2906065800 – ZR/T 55–90 Gear Casing Seal Kit for Oil-Free Compressors, 2906-0658-00.

Atlas Copco’s official page confirms 2906065800 as the ZR/T 55–90 Gearcasing Seal Kit.

Note: This part is different from 2906065600 and 2906065700: the 5600 is associated with the drive-shaft sealing arrangement, while the 5700 is the drive-shaft bearing kit; 2906065800 is specifically the gear-casing seal kit.