Definition of Jaw Coupling

A jaw coupling is a mechanical device used to connect two shafts in order to transmit torque while accommodating minor misalignments. It is commonly found in various mechanical systems due to its simplicity, reliability, and cost-effectiveness.

Types and Categories

Standard Jaw Coupling

Standard jaw couplings are the most basic type, consisting of two hubs and an elastomeric spider. They are suitable for general-purpose applications.

Curved Jaw Coupling

Curved jaw couplings have a more advanced design with curved jaws that provide better misalignment handling and vibration dampening.

Keyless Jaw Coupling

Keyless jaw couplings offer a more flexible and easy-to-install option, eliminating the need for keys and setscrews.

Components of Jaw Coupling

Hubs

The hubs are the parts of the coupling that attach to the shafts. They come in various designs to fit different shaft sizes and configurations.

Spider (Elastomer)

The spider, made from elastomeric material, sits between the hubs and absorbs vibrations and shocks, allowing for smooth torque transmission.

Setscrews

Setscrews are used to secure the hubs to the shafts, ensuring a tight and reliable connection.

Keyways

Keyways are slots in the hubs that accommodate keys, providing additional security against slippage.

Working Principle

Torque Transmission

Jaw couplings transmit torque from one shaft to another through the interlocking jaws and the elastomeric spider.

Misalignment Handling

They can handle minor angular, radial, and axial misalignments, protecting the machinery from excessive wear and tear.

Vibration Dampening

The elastomeric spider dampens vibrations, reducing noise and enhancing the smooth operation of the mechanical system.

Materials Used

Metal Hubs

Metal hubs, usually made of Cast Iron, steel or aluminium, provide strength and durability.

Elastomeric Spiders

Spiders are made from various elastomeric materials like rubber or polyurethane, chosen for their specific damping and flexibility properties.

Composite Materials

In some advanced applications, composite materials are used to enhance performance and reduce weight.

Advantages of Jaw Coupling

Cost-Effectiveness

Jaw couplings are relatively inexpensive, making them a popular choice for many applications.

Durability and Longevity

They are designed to last, with robust materials and construction that withstand harsh operating conditions.

Ease of Maintenance

Simple design and easy-to-replace components make maintenance straightforward and cost-effective.

Flexibility in Use

Jaw couplings are versatile and can be used in a wide range of applications, from light-duty to heavy-duty industrial machinery.

Disadvantages of Jaw Coupling

Limited Misalignment Capacity

While they can handle minor misalignments, jaw couplings are not suitable for applications with significant misalignment.

Potential for Wear and Tear

Over time, the elastomeric spider can wear out, requiring periodic replacement.

Performance Limitations in High-Speed Applications

In high-speed applications, jaw couplings might not perform as well as other types of couplings due to their design limitations.

Applications

Jaw couplings are widely used in various industrial machines, Pumps and Compressors, Conveyors and Material Handling

Installation and Maintenance

Installation Steps

  1. Align the shafts.
  2. Attach the hubs to the shafts.
  3. Insert the elastomeric spider.
  4. Secure the hubs with setscrews or keys.

Maintenance Tips

  • Regularly inspect for wear and tear.
  • Replace the elastomeric spider as needed.
  • Ensure proper alignment and tightness of setscrews.

Troubleshooting Common Issues

  • Misalignment: Check and correct shaft alignment.
  • Excessive vibration: Inspect and replace the elastomeric spider.
  • Slippage: Ensure setscrews or keys are properly tightened.