How to Choose a Chain Coupling: A 5-Step Guide

Step 1: Determine Torque and Select Size
This is the most critical step to prevent coupling failure.

• Calculate Required Torque: Use the formula: Torque (N-m) = [Power (kW) × 9550] / Speed (RPM).

• Apply a Service Factor: Multiply the calculated torque by a service factor based on the driven equipment. This accounts for shock loads and operational harshness.

  • *Examples: Agitators (1.5), Conveyors (1.7), Crushers (2.0+).*

• Match to Coupling Size: Select a chain coupling size (e.g., CC-50, CC-80) where its Rated Torque is greater than your calculated torque (with service factor). Consult the manufacturer’s torque table.

Step 2: Define Shaft & Speed Requirements

• Shaft Diameters & Keyways: Accurately measure the diameters of both the motor and driven machine shafts. Chain couplings consist of two sprocket-like hubs and a double-strand roller chain. Ensure the chosen hub size can accommodate your shaft diameters and keyways.

• Maximum RPM: Confirm your system’s maximum operating speed is below the coupling’s maximum speed rating. High speeds can cause centrifugal whipping of the chain.

Step 3: Assess Misalignment & Environment

• Misalignment Capacity: Chain couplings are good for moderate parallel misalignment and small amounts of angular misalignment. They are not suitable for axial misalignment.

• Environmental Conditions & Lubrication:

  • Lubrication is Required: This is the key maintenance point. A grease fitting is standard. The coupling must be lubricated regularly to minimize wear on the chain and sprocket teeth.

  • Temperature & Contaminants: Standard components are steel. For wet or corrosive environments, specify stainless steel hubs and a nickel-plated chain. For high temperatures, ensure the lubricant is rated accordingly. An optional cover can be used to retain lubricant and exclude dirt.

Step 4: Choose the Configuration

• Single Roller Chain: Standard design for general-purpose applications.

• Double Roller Chain: Provides higher torque capacity and better balance for more demanding applications.

Step 5: Finalize with a Trusted Supplier
Choose a supplier who provides:

• Clear Technical Data: Accurate torque and speed ratings.

• Material Options: Availability of standard steel or corrosion-resistant finishes.

• Sealing/Cover Options: Accessories to extend service life by protecting the chain.

Summary: Is a Chain Coupling Suitable for Your Use?

Choose a chain coupling if your application has:

• High Torque requirements at low to moderate speeds.

• Parallel Misalignment as the primary concern.

• A budget-conscious need for a robust and simple coupling.

• An operational plan for regular lubrication.

Reconsider a chain coupling if your application requires:

• Maintenance-free operation (consider a grid or jaw coupling).

• High-Speed operation (consider a disc coupling).

• Axial Misalignment compensation (consider a gear coupling).

Final Recommendation: The correct selection balances Torque, Speed, and Misalignment while accounting for the operating environment and maintenance schedule. Always consult the manufacturer’s catalog for precise sizing tables. When in doubt, provide your parameters (Torque, RPM, Shaft Sizes, Environment) to your supplier for a verified and guaranteed recommendation.