Flexible couplings are the most widely utilized category of shaft couplings. They are engineered to accommodate varying degrees of misalignment (angular, parallel, and axial) while transmitting torque and dampening system vibrations.
Types & Mechanisms:
Jaw (Spider) Coupling: Features an elastomeric insert (spider) sandwiched between two metallic hubs. This cost-effective design is renowned for its ability to dampen vibration and handle shock loads.
Gear Coupling: Consists of hubs with external teeth meshing with an internal sleeve. While torsionally rigid, the tooth profile allows for misalignment. These are typically specified for high-torque, heavy-duty applications.
Grid Coupling: Utilizes a corrugated steel grid that weaves through slots in the two hubs. This design provides excellent torsional flexibility and shock absorption.
Disc (Diaphragm) Coupling: Transmits torque through thin stainless steel discs or shims bolted between hubs. It offers zero backlash and requires no lubrication, making it ideal for high-speed, high-performance machinery.
Bellows Coupling: Features a thin-walled, accordion-like metal tube. This design delivers extreme torsional rigidity with zero backlash, making it the standard choice for precision servo motor applications.
Oldham Coupling: Utilizes a center sliding disc that mates with tenons on the hubs (tongue-and-groove). It is uniquely engineered to compensate for significant parallel misalignment.
Beam (Helical) Coupling: A single-piece construction featuring a spiral cut. This flexible design is primarily used for light-duty motion control, such as encoders and tachometers.
Universal Joint (U-Joint): A mechanical linkage capable of transmitting torque across large angles (up to 45°), commonly utilized in automotive driveshafts and agricultural machinery.
Tire Coupling: Features a highly flexible rubber or polyurethane "tire" element connecting the hubs. It excels at absorbing heavy shock loads and compensating for significant misalignment.