Atlas Copco Gear Preparations
Tool Preparation
Basic Tools: Socket wrench, torque wrench, hex key wrench, feeler gauge, dial indicator, puller (puller), copper rod, rubber hammer.
Auxiliary Tools: Cleaning cloth, lubricating oil (for gears), sealant, cleaning agent (such as kerosene or special cleaning agent).
Safety Equipment: Gloves, safety goggles, slip-resistant shoes.
Part Check
Confirm that the new gear kit (including the driving gear, driven gear, synchronous gear, etc.) has the same model, module, and tooth count as the original, and check if the tooth surface has burrs, cracks, or damage.
Prepare the matching wear parts: gear shaft bearings, sealing components (such as skeleton oil seals), locating pins, fastening bolts, etc.
Equipment Shutdown and Safety Measures
Turn off the air compressor power supply and hang a "Under Maintenance" warning sign.
Release the compressed air in the system (open the relief valve), and drain the lubricating oil in the oil separator.
Disassembly Steps
Remove external components
Remove the air compressor's protective cover, pulley (if belt-driven) or coupling, exposing the gearbox end cover.
Remove the fixing bolts of the gearbox end cover, gently tap the edge of the end cover with a rubber hammer to loosen it, and remove the end cover (note to preserve the sealing gasket).
Remove the old gear kit
Mark the relative position of the gear and the shaft (use a marker pen to mark), ensuring the phase is correct during installation (especially for synchronous gears).
Measure and record the meshing clearance (using a feeler gauge) and axial clearance (using a dial indicator) as a reference for installing the new gear.
Use a puller to remove the gear (if the gear has an interference fit with the shaft, you can slightly heat the outer ring of the gear to assist in removal, avoiding damage to the shaft diameter).
Synchronously remove the old bearings, oil seals, etc., clean the oil stains and iron filings in the shaft diameter and the gearbox (use cleaning agent for rinsing and drying).
Install the new gear kit
Preparation of Components
Check if the gear shaft diameter and the bearing seat surface are smooth, with no wear or scratches. If necessary, repair them (such as minor grinding).
The new bearings and gears can be coated with a small amount of lubricating oil to prevent rust. If it is an interference fit, heat the gear in 80-100°C hot oil for 5-10 minutes (or use a special heater) to facilitate installation.
Install the gear and bearings
Locate the gear according to the marking on the removal process and slowly insert it into the shaft diameter (avoid hard tapping, use a copper rod to gently tap the gear end face), ensure the axial positioning of the gear is accurate (if a distance ring needs to be installed, ensure it is flat and in close contact).
When installing the bearings, ensure the inner ring of the bearing fits with the shoulder of the shaft, and the outer ring fits with the bearing seat hole properly. Use a press or socket to evenly press it in (do not strike the rolling body of the bearing).
When installing the synchronous gears, strictly align the tooth surface markings to ensure the meshing phase of the two gears is consistent with the original factory (especially for the male and female rotor synchronous gears of the screw air compressor, which directly affects the rotor clearance).
Adjust the clearance
Meshing Clearance: Measure the side clearance at the meshing point of the gear with a feeler gauge. It should comply with the requirements of the equipment manual (usually 0.1-0.3mm, with significant differences for different models). If the clearance does not match, check the installation position of the gear or replace the adjustment pad.
Axial Clearance: Measure the axial movement of the gear with a dial indicator to ensure it is within the allowable range (generally ≤0.1mm). Adjust the thickness of the bearing end cover or the distance ring to achieve this.
Install the seal and end cover
Install the new sealing gasket or apply sealant in the sealing groove of the gearbox end cover (apply a thin layer evenly), ensuring the sealing surface is clean.
Align the locating pins of the end cover, evenly tighten the fixing bolts (follow the diagonal sequence and tighten the torque in accordance with the manual requirements) to prevent the end cover from deforming.
When installing the skeleton oil seal, pay attention to the lip orientation (usually towards the oil chamber side), use a special tool to press it in place, avoiding damage to the lip.
