Preparation before maintenance

1. Stop and cool down:

Ensure that the compressor has been completely shut down and cooled sufficiently to avoid injury or equipment damage due to high temperatures or pressure during maintenance.

2. Security measures:

Wear protective equipment such as hard hats, protective glasses, gloves, etc. to ensure safety during maintenance.

3. Preparation of tools and spare parts:

Prepare the tools, measuring instruments and spare parts required for maintenance, such as vernier calipers, micrometers, sandpaper, crankshaft grinders, etc.

crankshaft inspection

1. Macro Check:

Inspect the crankshaft neck and crankneck for defects such as deformation, strain, or burn.

Inspect crankshaft bearings and bearings for wear to ensure no excessive wear or damage.

2. Measurement check:

Use a vernier caliper or micrometer to measure the roundness, cylindricity, and surface roughness of the crankneck and crankneck.

Check the level value of the crankneck to ensure it is within the allowable range.

Carry out tinted and ultrasonic testing to check for defects such as cracks inside the crankshaft.

defect handling

1. Treatment of strains and burns:

For minor strains or burns, a fine flat file or oil stone can be used to remove the defects at the damaged site, and an emery cloth can be used to improve the surface roughness.

For more serious injuries, machining repairs, such as grinding, may be required.

2. Roundness and cylindricity over-difference treatment:

When the wear amount is less than or equal to 0.05mm, manual repair methods can be used, such as fine flat filing, cloth tape grinding, etc.

When the wear amount is greater than 0.05mm, machining repair is required, and grinding is performed on a crankshaft grinder or a special machine tool to restore the roundness and cylindricity of the journal.

3. Crack treatment:

For smaller cracks, an electric or pneumatic fine grinding wheel can be used to remove them, and a coloring test can be performed to confirm that the crack does not exist.

For larger cracks, cold patch repair may be required, with subsequent treatment to improve the surface roughness and strength of the repaired area.

Crankshaft Bending Alignment and Adjustment

1. Mechanical correction:

For small crankshafts with small bending, mechanical pressure or percussion can be used for correction.

Lift the crankshaft on the straightener, slowly apply force to the bending point with mechanical pressure, and correct from both ends of the deformed part to the middle section by section.

2. Thermal correction:

For large crankshafts or crankshafts with large bends, thermal correction or thermomechanical correction can be used.

Use the power frequency induction heating tool to heat the crankshaft, control the heating speed and heating temperature, and then perform cooling treatment to restore the straightness of the crankshaft.

Assembly and commissioning

1. Assembly:

After the crankshaft repair is completed, it should be assembled according to the assembly process and technical requirements.

Check and adjust the clearance and fit of the main bearing bush, connecting rod bush and other components to ensure the assembly quality.

2. Debugging:

After the assembly is completed, check the crankshaft to ensure that it can rotate easily.

Carry out air test and load test to check whether the operating state and performance parameters of the compressor meet the requirements.

Summary and Precautions

1. Summary:

The maintenance of the crankshaft of a reciprocating compressor is a complex and meticulous task, which requires the operation in strict accordance with the maintenance procedures and technical requirements.

Through scientific maintenance methods and reasonable repair measures, the performance and lifespan of the crankshaft can be restored and improved.

2. Precautions:

During the maintenance process, attention should be paid to the implementation of safety measures to avoid accidents.

For seriously worn or damaged crankshaft components, they should be replaced in a timely manner to avoid affecting the overall performance and operating safety of the compressor.

Strengthen the maintenance personnel business training and skills to improve the quality and efficiency of maintenance work.

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