Atlas Copco Gearbox Kit for GA90–160 Oil-Injected Screw Compressors Replacement – 2906097000

Atlas Copco 2906097000 – Gearbox Kit for GA90–160 Oil-Injected Screw Compressors

The Atlas Copco 2906097000 (2906-0970-00) is a Gearbox Kit designed for compatible GA90–160 stationary oil-injected screw compressors.

The gearbox is a critical mechanical transmission assembly that transfers rotational power from the compressor drive system to the compressor element at the required speed and torque. Correct gearbox operation is essential for maintaining efficient compressor performance, stable rotation and reliable compressed-air production.

The official Atlas Copco catalog lists the kit weight as 7.5 kg and identifies the kit for the GA product family / stationary oil-injected compressors.

Working Process:

During compressor operation, the electric motor produces rotational power.

This rotational power is transmitted through the compressor’s drive system to the gearbox.

The gearbox uses its internal gear arrangement to transmit the required torque and rotational speed to the compressor element.

The gearbox therefore ensures that the compressor element rotates at the required operating speed for efficient air compression.

As the compressor element rotates, atmospheric air enters the compressor through the inlet system.

The screw elements trap and compress the incoming air while the oil-injection system provides lubrication, cooling and sealing.

The compressed air/oil mixture then passes through the downstream separation and cooling system before compressed air is delivered to the network.

During continuous operation, the gearbox bearings and sealing components support smooth and reliable power transmission.

When the gearbox requires overhaul or maintenance, the worn bearings, shaft-sealing components and associated hardware are replaced using the 2906097000 Gearbox Kit.

Main Functions:

• Transfers rotational power to the compressor element.
• Maintains the required compressor-element speed.
• Supports efficient torque transmission.
• Provides mechanical support through gearbox bearings.
• Helps maintain correct shaft alignment.
• Supports reliable compressor operation.
• Helps restore gearbox performance during overhaul.
• Replaces critical worn gearbox components.
• Helps prevent bearing and shaft-seal related failures.

Official Kit Components:

Atlas Copco’s official catalog lists the following components in 2906097000:

• Bearing – 1 pc
• Parallel Key – 1 pc
• Shaft Seal Kit – 1 pc
• Circlip D = 80 – 1 pc
• Bearing – 1 pc
• Hexagon Screw – 8 pcs
• Parallel Key – 1 pc
• Dowty Seal Washer 1/2+ – 1 pc

The complete kit has an official listed weight of 7.5 kg.

Component Functions:

The bearings support the rotating gearbox shafts and allow smooth rotation while maintaining proper shaft alignment.

The parallel keys provide positive mechanical connection between the shaft and the relevant rotating components, allowing torque to be transferred without unwanted slippage.

The shaft seal kit prevents lubricating oil from escaping through the rotating shaft interface.

The circlip retains the relevant component in its specified position within the gearbox assembly.

The hexagon screws secure the gearbox components and maintain the mechanical integrity of the assembly.

The Dowty seal washer provides sealing at the applicable threaded connection and helps prevent oil leakage.

Gearbox Operating Cycle:

1. Motor Start: The electric motor starts and produces rotational power.
2. Power Transmission: Rotational power is transferred to the gearbox.
3. Gearbox Operation: The gearbox transmits the required torque and speed.
4. Shaft Rotation: The gearbox output shaft rotates the compressor element.
5. Air Intake: Atmospheric air enters the compressor.
6. Compression: The screw elements compress the incoming air.
7. Oil Injection: Oil provides cooling, lubrication and sealing during compression.
8. Air/Oil Separation: The compressed air/oil mixture passes through the separator system.
9. Compressed-Air Delivery: Treated compressed air is delivered to the air network.
10. Continuous Rotation: The gearbox continuously transmits power while the compressor operates.
11. Load/Unload Control: Compressor output changes according to system demand.
12. Shutdown: The gearbox stops when the compressor is stopped.

Importance of Gearbox Bearings:

The gearbox bearings support the rotating shafts and maintain their correct position.

If a bearing becomes worn, excessive clearance can develop.

This may result in:

• Increased vibration
• Abnormal gearbox noise
• Shaft misalignment
• Increased friction
• Increased operating temperature
• Gear wear
• Reduced gearbox efficiency
• Premature component failure

Replacing worn bearings during an overhaul helps restore smooth shaft rotation and correct mechanical alignment.

Importance of the Shaft Seal:

The shaft seal prevents lubricating oil from escaping around the rotating shaft.

Because the shaft continuously rotates, the seal must maintain effective sealing while allowing normal shaft movement.

A worn shaft seal may cause:

• Oil leakage
• Oil accumulation around the gearbox
• Increased oil consumption
• Contamination of surrounding components
• Reduced lubrication-system integrity

Replacing the shaft-seal kit during gearbox overhaul restores the sealing barrier around the shaft.

Role of Parallel Keys:

The parallel keys provide a positive mechanical connection between rotating components.

They allow torque to be transmitted from the shaft to the associated gearbox component.

A damaged or improperly fitted key can cause:

• Shaft-to-component movement
• Abnormal vibration
• Torque transmission problems
• Mechanical noise
• Accelerated shaft or hub wear

Correct key installation is therefore essential during gearbox assembly.

Possible Failure Conditions:

Long-term operation can cause wear of gearbox components.

Potential failure conditions include:

• Bearing wear
• Shaft-seal deterioration
• Gearbox vibration
• Shaft misalignment
• Key wear
• Loose fasteners
• Oil leakage
• Increased gearbox temperature
• Abnormal gearbox noise
• Excessive mechanical clearance

Typical compressor symptoms may include:

• Unusual gearbox noise.
• Increased vibration.
• Oil leakage near the gearbox.
• Increased gearbox temperature.
• Reduced compressor efficiency.
• Abnormal shaft rotation.
• Repeated bearing failures.
• Mechanical damage to connected components.

Maintenance / Gearbox Overhaul Procedure:

Before servicing the gearbox, stop the compressor, isolate the electrical supply and depressurize the compressor according to the applicable Atlas Copco safety procedure.

Allow the gearbox and lubricating oil to cool sufficiently before beginning work.

Inspect the gearbox for:

• Bearing condition
• Shaft condition
• Seal condition
• Key condition
• Circlip condition
• Fastener condition
• Oil leakage
• Gear wear
• Abnormal mechanical play
• Contamination

Remove the worn gearbox components carefully.

Clean the housing, shafts and mating surfaces.

Install the replacement components supplied in the 2906097000 Gearbox Kit according to the applicable Atlas Copco service documentation.

Ensure that:

• Bearings are correctly installed.
• Parallel keys are correctly positioned.
• Shaft seals are correctly oriented.
• The circlip is correctly seated.
• Hexagon screws are properly secured.
• The Dowty seal washer is correctly installed.
• Shafts rotate freely.
• Correct clearances are maintained.

After assembly, check the gearbox for smooth rotation before returning the compressor to service.

Restart the compressor according to the manufacturer’s procedure and monitor:

• Gearbox noise
• Vibration
• Oil leakage
• Gearbox temperature
• Compressor output
• Overall operating stability

A properly overhauled gearbox provides reliable power transmission and supports efficient operation of the compressor element.

The Atlas Copco 2906097000 Gearbox Kit therefore helps restore the mechanical integrity, bearing support, shaft sealing and torque-transmission performance of compatible GA90–160 compressor gearboxes.

Part Number: 2906097000
Alternative Number: 2906-0970-00 / 2906 0970 00
Brand: Atlas Copco
Official Description: Gearbox Kit
Application: GA90–160 stationary oil-injected screw compressors
Product Family: Atlas Copco GA / Stationary Oil-Injected Compressor
Kit Type: Gearbox overhaul/service kit
Official Listed Weight: 7.5 kg
Primary Function: Transmits rotational power to the compressor element
Secondary Functions: Supports shaft alignment, bearing operation and shaft sealing
Main Components: Bearings, parallel keys, shaft seal kit, circlip, hexagon screws and Dowty seal washer
Main Benefits: Restored power transmission, improved shaft support, reliable oil sealing, reduced vibration and dependable compressor operation.

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