What Are Couplings in Rotary Power Transmission?
A coupling connects two rotating components in a drive train to transfer rotational motion and torque.
In practical applications, couplings not only transmit power but also:
- Absorb misalignment, such as eccentricity (offset), declination (angular misalignment), and end play (axial displacement).
- Reduce assembly stress and vibration transmitted through connected shafts.
- Prevent damage to motors or machinery by releasing or deforming under excessive overload conditions.
Thus, couplings enhance the reliability, stability, and operational smoothness of mechanical systems.
Structural Variations
- Flexible Shaft Couplings: Designed to accommodate minor misalignments and absorb vibrations; ideal for servo and stepper motor connections.
- Rigid Shaft Couplings: For applications with precision alignment and where positional accuracy is crucial.
- Universal Joints: Used for large angular displacement, allowing rotary motion between non-collinear shafts.
- Chain and Flanged Couplings: Built for mechanical robustness, preferred in pumps, conveyors, and machinery drive systems.
Material and Customization Options
Most couplings are available in combinations of aluminum, steel, or stainless steel, depending on environmental and load conditions.
Companies (like MISUMI) provide customization options such as:
- Keyway grooving
- Key groove specifications (JIS/ISO)
- Shaft hole standards and bore tolerances
- Surface finishes or anti-corrosion treatments
Conclusion
Couplings enable efficient power transmission between rotating elements while offering flexibility and protection against misalignment and mechanical overload. With diverse designs—from flexible disk types to rigid and universal joints—couplings support a wide spectrum of mechanical requirements in modern machinery.
