Main Types and Applications
Elastic Coupling
Most common type: Widely used in small and medium-sized screw air compressors (such as the GA series), consisting of two half couplings and an intermediate elastic body (made of rubber or polyurethane).
Features:
Has certain elasticity, capable of absorbing installation deviations between the motor and the main unit (axial, radial and angular).
Reduces vibration transmission, lowers operating noise, and protects the motor and main unit bearings.
Simple structure, easy maintenance, and the elastic body can be replaced separately when worn.
Rigid Coupling
Application scenarios: A few large-sized or highly precise transmission models. Composed of metal rigid connection components.
Features:
No elastic compensation capability, requiring extremely high coaxiality between the motor and the main unit.
High torque transmission, suitable for high-power models, but strict requirements for installation accuracy.
Diaphragm Coupling
Application scenarios: Some high-end or large-scale units. Using metal diaphragms as the elastic element.
Features:
Resistant to high temperatures and oil contamination, long service life, suitable for harsh conditions.
Can compensate for certain deviations while maintaining high transmission accuracy. Core function
Torque transmission: Efficiently transfer the rotational power of the motor to the compressor main unit to ensure the normal operation of the main unit.
Deviation compensation: Allows for a small installation deviation between the motor and the main unit (such as displacement caused by temperature changes or vibration), avoiding damage to components due to rigid stress.
Vibration isolation: Absorbs vibrations through elastic elements, reduces the vibration transmission between the motor and the main unit, and extends the equipment lifespan.
Overload protection: The elastic body design of some couplings has an overload break function to prevent damage to the motor or the main unit due to instantaneous overload.
Common faults and replacement signals
Fault manifestations:
Abnormal vibration or abnormal noise occurs during operation (such as metal impact sounds, high-frequency noises).
Elastic body cracking, wear or aging (manifested as surface cracks, hardness changes).
Loosening or fracture of coupling connection bolts.
The motor and the main unit are not coaxial, causing wear or overheating of the coupling.
Replacement timing:
When the elastic body shows obvious wear, cracks or aging hardening.
When the components of the coupling (such as the semi-coupling) show deformation, cracks or thread damage.
It is recommended to inspect and replace according to the wear condition during major equipment maintenance (usually after 20,000 to 30,000 hours of operation).
Replacement and maintenance precautions
Original factory parts preferred: The dimensions, materials and precision of Atlas Copco couplings match specific models (such as the specifications of couplings for different power GA series are different), and only original factory parts must be used to avoid vibration or transmission failure due to size mismatch.
Installation accuracy:
When replacing, accurately correct the coaxiality of the motor and the main unit (radial and axial deviations are usually required to be ≤ 0.1mm), measure using a dial indicator, etc.
When installing the elastic body, ensure no distortion, and evenly tighten the bolts to the specified torque.
Regular inspection:
Check the condition of the elastic body, the tightness of the bolts and the operating temperature during daily maintenance.
Stop the machine in time when abnormal vibration is detected and check it promptly to avoid the expansion of the fault.
