Non‑Metallic Elastic Couplings
Elastomer‑based: Rubber, polyurethane, or plastic elements.
Advantages: Excellent damping, lightweight, low cost, electrical insulation, easy replacement.
Limitations: Lower temperature resistance (−20°C to +70°C typical), sensitive to oil, chemicals, and UV light.
Typical types:
Jaw (Plum‑shaped) coupling: Uses an elastomer spider between two jaw hubs; common in pumps and fans.
Tire coupling: Flexible rubber tire element; high misalignment capacity.
Elastic sleeve‑pin coupling: Rubber sleeves on pins; simple structure for medium loads.
Metallic Elastic Couplings
Metal‑based: Steel springs, diaphragms, or bellows.
Advantages: High strength, long service life, wide temperature range, resistance to oil and chemicals.
Limitations: Higher cost, lower damping than elastomers.
Typical types:
Diaphragm coupling: Single/multiple metal diaphragms; high precision for servo systems.
Snake spring (Geislinger) coupling: Steel spring packs; high torque and damping for heavy machinery.
Metal bellows coupling: Thin‑walled bellows; zero backlash for precision drives.
Key Advantages
Misalignment tolerance: Compensates for installation and operational shaft offsets.
Vibration isolation: Reduces noise and protects bearings and gears.
Shock absorption: Mitigates peak loads during startup, reversal, or overload.
Easy maintenance: Many designs allow elastomer replacement without disassembling shafts.
Versatility: Available in various sizes and torque ratings for diverse applications.
Typical Applications
Pumps & fans: Centrifugal pumps, blowers, compressors.
Motor & gearbox drives: Conveyors, mixers, crushers.
Automotive & marine: Engine‑transmission connections, ship propeller shafts.
Aerospace & precision machinery: Servo motors, robotics, machine tools.
Power generation: Turbines, generators.
Selection Considerations
When choosing an elastic coupling, evaluate:
Torque & speed: Nominal and peak torque, operating RPM.
Misalignment: Type and magnitude of axial, radial, and angular offset.
Environment: Temperature, humidity, exposure to oil, chemicals, or dust.
Space: Axial and radial installation constraints.
Maintenance: Service life and ease of element replacement.
Cost: Balance between performance and budget.
